tests/cases/compiler/promisePermutations.ts(74,70): error TS2345: Argument of type '(x: number) => IPromise<number>' is not assignable to parameter of type '(value: IPromise<number>) => IPromise<number>'.
  Types of parameters 'x' and 'value' are incompatible.
    Type 'number' is not assignable to type 'IPromise<number>'.
      Property 'then' is missing in type 'Number'.
tests/cases/compiler/promisePermutations.ts(79,19): error TS2345: Argument of type '(x: number, y?: string) => IPromise<string>' is not assignable to parameter of type '(value: string) => IPromise<string>'.
  Types of parameters 'x' and 'value' are incompatible.
    Type 'number' is not assignable to type 'string'.
tests/cases/compiler/promisePermutations.ts(82,19): error TS2345: Argument of type '(x: number, y?: string) => IPromise<string>' is not assignable to parameter of type '(value: string) => IPromise<string>'.
  Types of parameters 'x' and 'value' are incompatible.
    Type 'number' is not assignable to type 'string'.
tests/cases/compiler/promisePermutations.ts(83,19): error TS2345: Argument of type '(x: number, y?: string) => Promise<string>' is not assignable to parameter of type '(value: string) => Promise<string>'.
  Types of parameters 'x' and 'value' are incompatible.
    Type 'number' is not assignable to type 'string'.
tests/cases/compiler/promisePermutations.ts(84,19): error TS2345: Argument of type '(x: number, y?: string) => Promise<string>' is not assignable to parameter of type '(value: string) => IPromise<string>'.
  Types of parameters 'x' and 'value' are incompatible.
    Type 'number' is not assignable to type 'string'.
tests/cases/compiler/promisePermutations.ts(88,19): error TS2345: Argument of type '(x: number, cb: (a: string) => string) => IPromise<string>' is not assignable to parameter of type '(value: string) => IPromise<string>'.
tests/cases/compiler/promisePermutations.ts(91,19): error TS2345: Argument of type '(x: number, cb: (a: string) => string) => IPromise<string>' is not assignable to parameter of type '(value: string) => IPromise<string>'.
tests/cases/compiler/promisePermutations.ts(92,19): error TS2345: Argument of type '(x: number, cb: (a: string) => string) => Promise<string>' is not assignable to parameter of type '(value: string) => Promise<string>'.
tests/cases/compiler/promisePermutations.ts(93,19): error TS2345: Argument of type '(x: number, cb: (a: string) => string) => Promise<string>' is not assignable to parameter of type '(value: string) => IPromise<string>'.
tests/cases/compiler/promisePermutations.ts(97,19): error TS2345: Argument of type '(x: number, cb: <T>(a: T) => T) => IPromise<string>' is not assignable to parameter of type '(value: string) => IPromise<string>'.
tests/cases/compiler/promisePermutations.ts(100,19): error TS2345: Argument of type '(x: number, cb: <T>(a: T) => T) => IPromise<string>' is not assignable to parameter of type '(value: string) => IPromise<string>'.
tests/cases/compiler/promisePermutations.ts(101,19): error TS2345: Argument of type '(x: number, cb: <T>(a: T) => T) => Promise<string>' is not assignable to parameter of type '(value: string) => Promise<string>'.
tests/cases/compiler/promisePermutations.ts(102,19): error TS2345: Argument of type '(x: number, cb: <T>(a: T) => T) => Promise<string>' is not assignable to parameter of type '(value: string) => IPromise<string>'.
tests/cases/compiler/promisePermutations.ts(106,19): error TS2345: Argument of type '(cb: <T>(a: T) => T) => IPromise<string>' is not assignable to parameter of type '(value: string) => IPromise<string>'.
  Types of parameters 'cb' and 'value' are incompatible.
    Type '<T>(a: T) => T' is not assignable to type 'string'.
tests/cases/compiler/promisePermutations.ts(109,19): error TS2345: Argument of type '(cb: <T>(a: T) => T) => IPromise<string>' is not assignable to parameter of type '(value: string) => IPromise<string>'.
  Types of parameters 'cb' and 'value' are incompatible.
    Type '<T>(a: T) => T' is not assignable to type 'string'.
tests/cases/compiler/promisePermutations.ts(110,19): error TS2345: Argument of type '(cb: <T>(a: T) => T) => Promise<string>' is not assignable to parameter of type '(value: string) => Promise<string>'.
  Types of parameters 'cb' and 'value' are incompatible.
    Type '<T>(a: T) => T' is not assignable to type 'string'.
tests/cases/compiler/promisePermutations.ts(111,19): error TS2345: Argument of type '(cb: <T>(a: T) => T) => Promise<string>' is not assignable to parameter of type '(value: string) => IPromise<string>'.
  Types of parameters 'cb' and 'value' are incompatible.
    Type '<T>(a: T) => T' is not assignable to type 'string'.
tests/cases/compiler/promisePermutations.ts(117,19): error TS2345: Argument of type '<T>(x: T, cb: (a: T) => T) => IPromise<T>' is not assignable to parameter of type '(value: number) => IPromise<number>'.
tests/cases/compiler/promisePermutations.ts(120,19): error TS2345: Argument of type '<T>(x: T, cb: (a: T) => T) => IPromise<T>' is not assignable to parameter of type '(value: number) => IPromise<number>'.
tests/cases/compiler/promisePermutations.ts(121,19): error TS2345: Argument of type '<T>(x: T, cb: (a: T) => T) => Promise<T>' is not assignable to parameter of type '(value: number) => Promise<number>'.
tests/cases/compiler/promisePermutations.ts(122,19): error TS2345: Argument of type '<T>(x: T, cb: (a: T) => T) => Promise<T>' is not assignable to parameter of type '(value: number) => IPromise<any>'.
tests/cases/compiler/promisePermutations.ts(126,19): error TS2345: Argument of type '<T>(x: T, cb: <U>(a: U) => U) => IPromise<T>' is not assignable to parameter of type '(value: number) => IPromise<number>'.
tests/cases/compiler/promisePermutations.ts(129,11): error TS2453: The type argument for type parameter 'U' cannot be inferred from the usage. Consider specifying the type arguments explicitly.
  Type argument candidate 'IPromise<number>' is not a valid type argument because it is not a supertype of candidate 'IPromise<string>'.
    Type 'string' is not assignable to type 'number'.
tests/cases/compiler/promisePermutations.ts(132,19): error TS2345: Argument of type '<T>(x: T, cb: <U>(a: U) => U) => IPromise<T>' is not assignable to parameter of type '(value: number) => IPromise<number>'.
tests/cases/compiler/promisePermutations.ts(133,19): error TS2345: Argument of type '<T>(x: T, cb: <U>(a: U) => U) => Promise<T>' is not assignable to parameter of type '(value: number) => Promise<number>'.
tests/cases/compiler/promisePermutations.ts(134,19): error TS2345: Argument of type '<T>(x: T, cb: <U>(a: U) => U) => Promise<T>' is not assignable to parameter of type '(value: number) => IPromise<any>'.
tests/cases/compiler/promisePermutations.ts(137,11): error TS2453: The type argument for type parameter 'U' cannot be inferred from the usage. Consider specifying the type arguments explicitly.
  Type argument candidate 'IPromise<number>' is not a valid type argument because it is not a supertype of candidate 'IPromise<string>'.
    Type 'string' is not assignable to type 'number'.
tests/cases/compiler/promisePermutations.ts(144,12): error TS2453: The type argument for type parameter 'U' cannot be inferred from the usage. Consider specifying the type arguments explicitly.
  Type argument candidate 'IPromise<number>' is not a valid type argument because it is not a supertype of candidate 'IPromise<string>'.
    Type 'string' is not assignable to type 'number'.
tests/cases/compiler/promisePermutations.ts(152,12): error TS2453: The type argument for type parameter 'U' cannot be inferred from the usage. Consider specifying the type arguments explicitly.
  Type argument candidate 'Promise<number>' is not a valid type argument because it is not a supertype of candidate 'IPromise<string>'.
    Types of property 'then' are incompatible.
      Type '{ <U>(success?: (value: string) => IPromise<U>, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: string) => IPromise<U>, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: string) => U, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: string) => U, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; }' is not assignable to type '{ <U>(success?: (value: number) => Promise<U>, error?: (error: any) => Promise<U>, progress?: (progress: any) => void): Promise<U>; <U>(success?: (value: number) => Promise<U>, error?: (error: any) => U, progress?: (progress: any) => void): Promise<U>; <U>(success?: (value: number) => U, error?: (error: any) => Promise<U>, progress?: (progress: any) => void): Promise<U>; <U>(success?: (value: number) => U, error?: (error: any) => U, progress?: (progress: any) => void): Promise<U>; }'.
        Types of parameters 'success' and 'success' are incompatible.
          Type '(value: string) => IPromise<any>' is not assignable to type '(value: number) => Promise<any>'.
            Types of parameters 'value' and 'value' are incompatible.
              Type 'string' is not assignable to type 'number'.
tests/cases/compiler/promisePermutations.ts(156,21): error TS2345: Argument of type '{ (x: number): IPromise<number>; (x: string): IPromise<string>; }' is not assignable to parameter of type '(value: number) => IPromise<string>'.
  Type 'IPromise<number>' is not assignable to type 'IPromise<string>'.
    Type 'number' is not assignable to type 'string'.
tests/cases/compiler/promisePermutations.ts(158,21): error TS2345: Argument of type '{ (x: number): IPromise<number>; (x: string): IPromise<string>; }' is not assignable to parameter of type '(value: number) => IPromise<string>'.
  Type 'IPromise<number>' is not assignable to type 'IPromise<string>'.
    Type 'number' is not assignable to type 'string'.
tests/cases/compiler/promisePermutations.ts(159,21): error TS2345: Argument of type '{ (x: number): Promise<number>; (x: string): Promise<string>; }' is not assignable to parameter of type '(value: number) => Promise<string>'.
  Type 'Promise<number>' is not assignable to type 'Promise<string>'.
    Type 'number' is not assignable to type 'string'.
tests/cases/compiler/promisePermutations.ts(160,21): error TS2345: Argument of type '{ (x: number): Promise<number>; (x: string): Promise<string>; }' is not assignable to parameter of type '(value: number) => IPromise<string>'.
  Type 'Promise<number>' is not assignable to type 'IPromise<string>'.
    Types of property 'then' are incompatible.
      Type '{ <U>(success?: (value: number) => Promise<U>, error?: (error: any) => Promise<U>, progress?: (progress: any) => void): Promise<U>; <U>(success?: (value: number) => Promise<U>, error?: (error: any) => U, progress?: (progress: any) => void): Promise<U>; <U>(success?: (value: number) => U, error?: (error: any) => Promise<U>, progress?: (progress: any) => void): Promise<U>; <U>(success?: (value: number) => U, error?: (error: any) => U, progress?: (progress: any) => void): Promise<U>; }' is not assignable to type '{ <U>(success?: (value: string) => IPromise<U>, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: string) => IPromise<U>, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: string) => U, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: string) => U, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; }'.
        Types of parameters 'success' and 'success' are incompatible.
          Type '(value: number) => Promise<any>' is not assignable to type '(value: string) => IPromise<any>'.
            Types of parameters 'value' and 'value' are incompatible.
              Type 'number' is not assignable to type 'string'.


==== tests/cases/compiler/promisePermutations.ts (33 errors) ====
    interface Promise<T> {
        then<U>(success?: (value: T) => Promise<U>, error?: (error: any) => Promise<U>, progress?: (progress: any) => void): Promise<U>;
        then<U>(success?: (value: T) => Promise<U>, error?: (error: any) => U, progress?: (progress: any) => void): Promise<U>;
        then<U>(success?: (value: T) => U, error?: (error: any) => Promise<U>, progress?: (progress: any) => void): Promise<U>;
        then<U>(success?: (value: T) => U, error?: (error: any) => U, progress?: (progress: any) => void): Promise<U>;
        done<U>(success?: (value: T) => any, error?: (error: any) => any, progress?: (progress: any) => void): void;
    }
    
    interface IPromise<T> {
        then<U>(success?: (value: T) => IPromise<U>, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>;
        then<U>(success?: (value: T) => IPromise<U>, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>;
        then<U>(success?: (value: T) => U, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>;
        then<U>(success?: (value: T) => U, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>;
        done? <U>(success?: (value: T) => any, error?: (error: any) => any, progress?: (progress: any) => void): void;
    }
    
    declare function testFunction(): IPromise<number>;
    declare function testFunctionP(): Promise<number>;
    declare function testFunction2(): IPromise<{ x: number }>;
    declare function testFunction2P(): Promise<{ x: number }>;
    declare function testFunction3(x: number): IPromise<number>;
    declare function testFunction3P(x: number): Promise<number>;
    declare function testFunction4(x: number, y?: string): IPromise<string>;
    declare function testFunction4P(x: number, y?: string): Promise<string>;
    declare function testFunction5(x: number, cb: (a: string) => string): IPromise<string>;
    declare function testFunction5P(x: number, cb: (a: string) => string): Promise<string>;
    declare function testFunction6(x: number, cb: <T>(a: T) => T): IPromise<string>;
    declare function testFunction6P(x: number, cb: <T>(a: T) => T): Promise<string>;
    declare function testFunction7(cb: <T>(a: T) => T): IPromise<string>;
    declare function testFunction7P(cb: <T>(a: T) => T): Promise<string>;
    declare function testFunction8<T>(x: T, cb: (a: T) => T): IPromise<T>;
    declare function testFunction8P<T>(x: T, cb: (a: T) => T): Promise<T>;
    declare function testFunction9<T>(x: T, cb: <U>(a: U) => U): IPromise<T>;
    declare function testFunction9P<T>(x: T, cb: <U>(a: U) => U): Promise<T>;
    declare function testFunction10<T>(cb: <U>(a: U) => U): IPromise<T>;
    declare function testFunction10P<T>(cb: <U>(a: U) => U): Promise<T>;
    
    declare function testFunction11(x: number): IPromise<number>;
    declare function testFunction11(x: string): IPromise<string>;
    declare function testFunction11P(x: number): Promise<number>;
    declare function testFunction11P(x: string): Promise<string>;
    
    declare function testFunction12<T>(x: T): IPromise<T>;
    declare function testFunction12<T>(x: T, y: T): IPromise<T>;
    declare function testFunction12P<T>(x: T): IPromise<T>;
    declare function testFunction12P<T>(x: T, y: T): Promise<T>;
    
    var r1: IPromise<number>;
    var r1a = r1.then(testFunction, testFunction, testFunction);
    var r1b = r1.then(testFunction, testFunction, testFunction).then(testFunction, testFunction, testFunction);
    var r1c = r1.then(testFunctionP, testFunctionP, testFunctionP);
    var s1: Promise<number>;
    var s1a = s1.then(testFunction, testFunction, testFunction);
    var s1b = s1.then(testFunctionP, testFunctionP, testFunctionP);
    var s1c = s1.then(testFunctionP, testFunction, testFunction);
    var s1d = s1.then(testFunctionP, testFunction, testFunction).then(testFunction, testFunction, testFunction);
    
    var r2: IPromise<{ x: number; }>;
    var r2a = r2.then(testFunction2, testFunction2, testFunction2);
    var r2b = r2.then(testFunction2, testFunction2, testFunction2).then(testFunction2, testFunction2, testFunction2);
    var s2: Promise<{ x: number; }>;
    var s2a = s2.then(testFunction2, testFunction2, testFunction2);
    var s2b = s2.then(testFunction2P, testFunction2P, testFunction2P);
    var s2c = s2.then(testFunction2P, testFunction2, testFunction2);
    var s2d = s2.then(testFunction2P, testFunction2, testFunction2).then(testFunction2, testFunction2, testFunction2);
    
    var r3: IPromise<number>;
    var r3a = r3.then(testFunction3, testFunction3, testFunction3);
    var r3b = r3.then(testFunction3, testFunction3, testFunction3).then(testFunction3, testFunction3, testFunction3);
    var s3: Promise<number>;
    var s3a = s3.then(testFunction3, testFunction3, testFunction3);
    var s3b = s3.then(testFunction3P, testFunction3P, testFunction3P);
    var s3c = s3.then(testFunction3P, testFunction3, testFunction3);
    var s3d = s3.then(testFunction3P, testFunction3, testFunction3).then(testFunction3, testFunction3, testFunction3); // error
                                                                         ~~~~~~~~~~~~~
!!! error TS2345: Argument of type '(x: number) => IPromise<number>' is not assignable to parameter of type '(value: IPromise<number>) => IPromise<number>'.
!!! error TS2345:   Types of parameters 'x' and 'value' are incompatible.
!!! error TS2345:     Type 'number' is not assignable to type 'IPromise<number>'.
!!! error TS2345:       Property 'then' is missing in type 'Number'.
    
    var r4: IPromise<string>;
    var sIPromise: (x: any) => IPromise<string>;
    var sPromise: (x: any) => Promise<string>;
    var r4a = r4.then(testFunction4, testFunction4, testFunction4); // error
                      ~~~~~~~~~~~~~
!!! error TS2345: Argument of type '(x: number, y?: string) => IPromise<string>' is not assignable to parameter of type '(value: string) => IPromise<string>'.
!!! error TS2345:   Types of parameters 'x' and 'value' are incompatible.
!!! error TS2345:     Type 'number' is not assignable to type 'string'.
    var r4b = r4.then(sIPromise, testFunction4, testFunction4).then(sIPromise, testFunction4, testFunction4); // ok
    var s4: Promise<string>;
    var s4a = s4.then(testFunction4, testFunction4, testFunction4); // error
                      ~~~~~~~~~~~~~
!!! error TS2345: Argument of type '(x: number, y?: string) => IPromise<string>' is not assignable to parameter of type '(value: string) => IPromise<string>'.
!!! error TS2345:   Types of parameters 'x' and 'value' are incompatible.
!!! error TS2345:     Type 'number' is not assignable to type 'string'.
    var s4b = s4.then(testFunction4P, testFunction4P, testFunction4P); // error 
                      ~~~~~~~~~~~~~~
!!! error TS2345: Argument of type '(x: number, y?: string) => Promise<string>' is not assignable to parameter of type '(value: string) => Promise<string>'.
!!! error TS2345:   Types of parameters 'x' and 'value' are incompatible.
!!! error TS2345:     Type 'number' is not assignable to type 'string'.
    var s4c = s4.then(testFunction4P, testFunction4, testFunction4); // error
                      ~~~~~~~~~~~~~~
!!! error TS2345: Argument of type '(x: number, y?: string) => Promise<string>' is not assignable to parameter of type '(value: string) => IPromise<string>'.
!!! error TS2345:   Types of parameters 'x' and 'value' are incompatible.
!!! error TS2345:     Type 'number' is not assignable to type 'string'.
    var s4d = s4.then(sIPromise, testFunction4P, testFunction4).then(sIPromise, testFunction4P, testFunction4);
    
    var r5: IPromise<string>;
    var r5a = r5.then(testFunction5, testFunction5, testFunction5); // error
                      ~~~~~~~~~~~~~
!!! error TS2345: Argument of type '(x: number, cb: (a: string) => string) => IPromise<string>' is not assignable to parameter of type '(value: string) => IPromise<string>'.
    var r5b = r5.then(sIPromise, sIPromise, sIPromise).then(sIPromise, sIPromise, sIPromise); // ok
    var s5: Promise<string>;
    var s5a = s5.then(testFunction5, testFunction5, testFunction5); // error
                      ~~~~~~~~~~~~~
!!! error TS2345: Argument of type '(x: number, cb: (a: string) => string) => IPromise<string>' is not assignable to parameter of type '(value: string) => IPromise<string>'.
    var s5b = s5.then(testFunction5P, testFunction5P, testFunction5P); // error
                      ~~~~~~~~~~~~~~
!!! error TS2345: Argument of type '(x: number, cb: (a: string) => string) => Promise<string>' is not assignable to parameter of type '(value: string) => Promise<string>'.
    var s5c = s5.then(testFunction5P, testFunction5, testFunction5); // error
                      ~~~~~~~~~~~~~~
!!! error TS2345: Argument of type '(x: number, cb: (a: string) => string) => Promise<string>' is not assignable to parameter of type '(value: string) => IPromise<string>'.
    var s5d = s5.then(sPromise, sPromise, sPromise).then(sIPromise, sIPromise, sIPromise); // ok
    
    var r6: IPromise<string>;
    var r6a = r6.then(testFunction6, testFunction6, testFunction6); // error
                      ~~~~~~~~~~~~~
!!! error TS2345: Argument of type '(x: number, cb: <T>(a: T) => T) => IPromise<string>' is not assignable to parameter of type '(value: string) => IPromise<string>'.
    var r6b = r6.then(sIPromise, sIPromise, sIPromise).then(sIPromise, sIPromise, sIPromise); // ok
    var s6: Promise<string>;
    var s6a = s6.then(testFunction6, testFunction6, testFunction6); // error
                      ~~~~~~~~~~~~~
!!! error TS2345: Argument of type '(x: number, cb: <T>(a: T) => T) => IPromise<string>' is not assignable to parameter of type '(value: string) => IPromise<string>'.
    var s6b = s6.then(testFunction6P, testFunction6P, testFunction6P); // error
                      ~~~~~~~~~~~~~~
!!! error TS2345: Argument of type '(x: number, cb: <T>(a: T) => T) => Promise<string>' is not assignable to parameter of type '(value: string) => Promise<string>'.
    var s6c = s6.then(testFunction6P, testFunction6, testFunction6); // error
                      ~~~~~~~~~~~~~~
!!! error TS2345: Argument of type '(x: number, cb: <T>(a: T) => T) => Promise<string>' is not assignable to parameter of type '(value: string) => IPromise<string>'.
    var s6d = s6.then(sPromise, sPromise, sPromise).then(sIPromise, sIPromise, sIPromise); // ok
    
    var r7: IPromise<string>;
    var r7a = r7.then(testFunction7, testFunction7, testFunction7); // error
                      ~~~~~~~~~~~~~
!!! error TS2345: Argument of type '(cb: <T>(a: T) => T) => IPromise<string>' is not assignable to parameter of type '(value: string) => IPromise<string>'.
!!! error TS2345:   Types of parameters 'cb' and 'value' are incompatible.
!!! error TS2345:     Type '<T>(a: T) => T' is not assignable to type 'string'.
    var r7b = r7.then(sIPromise, sIPromise, sIPromise).then(sIPromise, sIPromise, sIPromise); // ok
    var s7: Promise<string>;
    var s7a = r7.then(testFunction7, testFunction7, testFunction7); // error
                      ~~~~~~~~~~~~~
!!! error TS2345: Argument of type '(cb: <T>(a: T) => T) => IPromise<string>' is not assignable to parameter of type '(value: string) => IPromise<string>'.
!!! error TS2345:   Types of parameters 'cb' and 'value' are incompatible.
!!! error TS2345:     Type '<T>(a: T) => T' is not assignable to type 'string'.
    var s7b = r7.then(testFunction7P, testFunction7P, testFunction7P); // error
                      ~~~~~~~~~~~~~~
!!! error TS2345: Argument of type '(cb: <T>(a: T) => T) => Promise<string>' is not assignable to parameter of type '(value: string) => Promise<string>'.
!!! error TS2345:   Types of parameters 'cb' and 'value' are incompatible.
!!! error TS2345:     Type '<T>(a: T) => T' is not assignable to type 'string'.
    var s7c = r7.then(testFunction7P, testFunction7, testFunction7); // error
                      ~~~~~~~~~~~~~~
!!! error TS2345: Argument of type '(cb: <T>(a: T) => T) => Promise<string>' is not assignable to parameter of type '(value: string) => IPromise<string>'.
!!! error TS2345:   Types of parameters 'cb' and 'value' are incompatible.
!!! error TS2345:     Type '<T>(a: T) => T' is not assignable to type 'string'.
    var s7d = r7.then(sPromise, sPromise, sPromise).then(sPromise, sPromise, sPromise); // ok?
    
    var r8: IPromise<number>;
    var nIPromise: (x: any) => IPromise<number>;
    var nPromise: (x: any) => Promise<number>;
    var r8a = r8.then(testFunction8, testFunction8, testFunction8); // error
                      ~~~~~~~~~~~~~
!!! error TS2345: Argument of type '<T>(x: T, cb: (a: T) => T) => IPromise<T>' is not assignable to parameter of type '(value: number) => IPromise<number>'.
    var r8b = r8.then(nIPromise, nIPromise, nIPromise).then(nIPromise, nIPromise, nIPromise); // ok
    var s8: Promise<number>;
    var s8a = s8.then(testFunction8, testFunction8, testFunction8); // error
                      ~~~~~~~~~~~~~
!!! error TS2345: Argument of type '<T>(x: T, cb: (a: T) => T) => IPromise<T>' is not assignable to parameter of type '(value: number) => IPromise<number>'.
    var s8b = s8.then(testFunction8P, testFunction8P, testFunction8P); // error
                      ~~~~~~~~~~~~~~
!!! error TS2345: Argument of type '<T>(x: T, cb: (a: T) => T) => Promise<T>' is not assignable to parameter of type '(value: number) => Promise<number>'.
    var s8c = s8.then(testFunction8P, testFunction8, testFunction8); // error
                      ~~~~~~~~~~~~~~
!!! error TS2345: Argument of type '<T>(x: T, cb: (a: T) => T) => Promise<T>' is not assignable to parameter of type '(value: number) => IPromise<any>'.
    var s8d = s8.then(nIPromise, nIPromise, nIPromise).then(nIPromise, nIPromise, nIPromise); // ok
    
    var r9: IPromise<number>;
    var r9a = r9.then(testFunction9, testFunction9, testFunction9); // error
                      ~~~~~~~~~~~~~
!!! error TS2345: Argument of type '<T>(x: T, cb: <U>(a: U) => U) => IPromise<T>' is not assignable to parameter of type '(value: number) => IPromise<number>'.
    var r9b = r9.then(sIPromise, sIPromise, sIPromise); // ok
    var r9c = r9.then(nIPromise, nIPromise, nIPromise); // ok
    var r9d = r9.then(testFunction, sIPromise, nIPromise); // ok
              ~~~~~~~
!!! error TS2453: The type argument for type parameter 'U' cannot be inferred from the usage. Consider specifying the type arguments explicitly.
!!! error TS2453:   Type argument candidate 'IPromise<number>' is not a valid type argument because it is not a supertype of candidate 'IPromise<string>'.
!!! error TS2453:     Type 'string' is not assignable to type 'number'.
    var r9e = r9.then(testFunction, nIPromise, sIPromise).then(sIPromise, sIPromise, sIPromise); // ok
    var s9: Promise<number>;
    var s9a = s9.then(testFunction9, testFunction9, testFunction9); // error
                      ~~~~~~~~~~~~~
!!! error TS2345: Argument of type '<T>(x: T, cb: <U>(a: U) => U) => IPromise<T>' is not assignable to parameter of type '(value: number) => IPromise<number>'.
    var s9b = s9.then(testFunction9P, testFunction9P, testFunction9P); // error
                      ~~~~~~~~~~~~~~
!!! error TS2345: Argument of type '<T>(x: T, cb: <U>(a: U) => U) => Promise<T>' is not assignable to parameter of type '(value: number) => Promise<number>'.
    var s9c = s9.then(testFunction9P, testFunction9, testFunction9); // error
                      ~~~~~~~~~~~~~~
!!! error TS2345: Argument of type '<T>(x: T, cb: <U>(a: U) => U) => Promise<T>' is not assignable to parameter of type '(value: number) => IPromise<any>'.
    var s9d = s9.then(sPromise, sPromise, sPromise); // ok
    var s9e = s9.then(nPromise, nPromise, nPromise); // ok
    var s9f = s9.then(testFunction, sIPromise, nIPromise); // error
              ~~~~~~~
!!! error TS2453: The type argument for type parameter 'U' cannot be inferred from the usage. Consider specifying the type arguments explicitly.
!!! error TS2453:   Type argument candidate 'IPromise<number>' is not a valid type argument because it is not a supertype of candidate 'IPromise<string>'.
!!! error TS2453:     Type 'string' is not assignable to type 'number'.
    var s9g = s9.then(testFunction, nIPromise, sIPromise).then(sIPromise, sIPromise, sIPromise); // ok
    
    var r10 = testFunction10(x => x);
    var r10a = r10.then(testFunction10, testFunction10, testFunction10); // ok
    var r10b = r10.then(sIPromise, sIPromise, sIPromise); // ok
    var r10c = r10.then(nIPromise, nIPromise, nIPromise); // ok
    var r10d = r10.then(testFunction, sIPromise, nIPromise); // ok
               ~~~~~~~~
!!! error TS2453: The type argument for type parameter 'U' cannot be inferred from the usage. Consider specifying the type arguments explicitly.
!!! error TS2453:   Type argument candidate 'IPromise<number>' is not a valid type argument because it is not a supertype of candidate 'IPromise<string>'.
!!! error TS2453:     Type 'string' is not assignable to type 'number'.
    var r10e = r10.then(testFunction, nIPromise, sIPromise).then(sIPromise, sIPromise, sIPromise); // ok
    var s10 = testFunction10P(x => x);
    var s10a = s10.then(testFunction10, testFunction10, testFunction10); // ok
    var s10b = s10.then(testFunction10P, testFunction10P, testFunction10P); // ok
    var s10c = s10.then(testFunction10P, testFunction10, testFunction10); // ok
    var s10d = s10.then(sPromise, sPromise, sPromise); // ok
    var s10e = s10.then(nIPromise, nPromise, nIPromise); // ok
    var s10f = s10.then(testFunctionP, sIPromise, nIPromise); // error
               ~~~~~~~~
!!! error TS2453: The type argument for type parameter 'U' cannot be inferred from the usage. Consider specifying the type arguments explicitly.
!!! error TS2453:   Type argument candidate 'Promise<number>' is not a valid type argument because it is not a supertype of candidate 'IPromise<string>'.
!!! error TS2453:     Types of property 'then' are incompatible.
!!! error TS2453:       Type '{ <U>(success?: (value: string) => IPromise<U>, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: string) => IPromise<U>, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: string) => U, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: string) => U, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; }' is not assignable to type '{ <U>(success?: (value: number) => Promise<U>, error?: (error: any) => Promise<U>, progress?: (progress: any) => void): Promise<U>; <U>(success?: (value: number) => Promise<U>, error?: (error: any) => U, progress?: (progress: any) => void): Promise<U>; <U>(success?: (value: number) => U, error?: (error: any) => Promise<U>, progress?: (progress: any) => void): Promise<U>; <U>(success?: (value: number) => U, error?: (error: any) => U, progress?: (progress: any) => void): Promise<U>; }'.
!!! error TS2453:         Types of parameters 'success' and 'success' are incompatible.
!!! error TS2453:           Type '(value: string) => IPromise<any>' is not assignable to type '(value: number) => Promise<any>'.
!!! error TS2453:             Types of parameters 'value' and 'value' are incompatible.
!!! error TS2453:               Type 'string' is not assignable to type 'number'.
    var s10g = s10.then(testFunctionP, nIPromise, sIPromise).then(sPromise, sIPromise, sIPromise); // ok
    
    var r11: IPromise<number>;
    var r11a = r11.then(testFunction11, testFunction11, testFunction11); // error
                        ~~~~~~~~~~~~~~
!!! error TS2345: Argument of type '{ (x: number): IPromise<number>; (x: string): IPromise<string>; }' is not assignable to parameter of type '(value: number) => IPromise<string>'.
!!! error TS2345:   Type 'IPromise<number>' is not assignable to type 'IPromise<string>'.
!!! error TS2345:     Type 'number' is not assignable to type 'string'.
    var s11: Promise<number>;
    var s11a = s11.then(testFunction11, testFunction11, testFunction11); // ok
                        ~~~~~~~~~~~~~~
!!! error TS2345: Argument of type '{ (x: number): IPromise<number>; (x: string): IPromise<string>; }' is not assignable to parameter of type '(value: number) => IPromise<string>'.
!!! error TS2345:   Type 'IPromise<number>' is not assignable to type 'IPromise<string>'.
!!! error TS2345:     Type 'number' is not assignable to type 'string'.
    var s11b = s11.then(testFunction11P, testFunction11P, testFunction11P); // error
                        ~~~~~~~~~~~~~~~
!!! error TS2345: Argument of type '{ (x: number): Promise<number>; (x: string): Promise<string>; }' is not assignable to parameter of type '(value: number) => Promise<string>'.
!!! error TS2345:   Type 'Promise<number>' is not assignable to type 'Promise<string>'.
!!! error TS2345:     Type 'number' is not assignable to type 'string'.
    var s11c = s11.then(testFunction11P, testFunction11, testFunction11); // error
                        ~~~~~~~~~~~~~~~
!!! error TS2345: Argument of type '{ (x: number): Promise<number>; (x: string): Promise<string>; }' is not assignable to parameter of type '(value: number) => IPromise<string>'.
!!! error TS2345:   Type 'Promise<number>' is not assignable to type 'IPromise<string>'.
!!! error TS2345:     Types of property 'then' are incompatible.
!!! error TS2345:       Type '{ <U>(success?: (value: number) => Promise<U>, error?: (error: any) => Promise<U>, progress?: (progress: any) => void): Promise<U>; <U>(success?: (value: number) => Promise<U>, error?: (error: any) => U, progress?: (progress: any) => void): Promise<U>; <U>(success?: (value: number) => U, error?: (error: any) => Promise<U>, progress?: (progress: any) => void): Promise<U>; <U>(success?: (value: number) => U, error?: (error: any) => U, progress?: (progress: any) => void): Promise<U>; }' is not assignable to type '{ <U>(success?: (value: string) => IPromise<U>, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: string) => IPromise<U>, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: string) => U, error?: (error: any) => IPromise<U>, progress?: (progress: any) => void): IPromise<U>; <U>(success?: (value: string) => U, error?: (error: any) => U, progress?: (progress: any) => void): IPromise<U>; }'.
!!! error TS2345:         Types of parameters 'success' and 'success' are incompatible.
!!! error TS2345:           Type '(value: number) => Promise<any>' is not assignable to type '(value: string) => IPromise<any>'.
!!! error TS2345:             Types of parameters 'value' and 'value' are incompatible.
!!! error TS2345:               Type 'number' is not assignable to type 'string'.
    
    var r12 = testFunction12(x => x);
    var r12a = r12.then(testFunction12, testFunction12, testFunction12); // ok
    var s12 = testFunction12(x => x);
    var s12a = s12.then(testFunction12, testFunction12, testFunction12); // ok
    var s12b = s12.then(testFunction12P, testFunction12P, testFunction12P); // ok
    var s12c = s12.then(testFunction12P, testFunction12, testFunction12); // ok