=== tests/cases/conformance/types/typeRelationships/subtypesAndSuperTypes/subtypingWithOptionalProperties.ts ===
// subtyping is not transitive due to optional properties but the subtyping algorithm assumes it is for the 99% case

// returns { s?: number; }
function f<T>(a: T) {
>f : Symbol(f, Decl(subtypingWithOptionalProperties.ts, 0, 0))
>T : Symbol(T, Decl(subtypingWithOptionalProperties.ts, 3, 11))
>a : Symbol(a, Decl(subtypingWithOptionalProperties.ts, 3, 14))
>T : Symbol(T, Decl(subtypingWithOptionalProperties.ts, 3, 11))

    var b: { s?: number } = a;
>b : Symbol(b, Decl(subtypingWithOptionalProperties.ts, 4, 7))
>s : Symbol(s, Decl(subtypingWithOptionalProperties.ts, 4, 12))
>a : Symbol(a, Decl(subtypingWithOptionalProperties.ts, 3, 14))

    return b;
>b : Symbol(b, Decl(subtypingWithOptionalProperties.ts, 4, 7))
}

var r = f({ s: new Object() }); // ok
>r : Symbol(r, Decl(subtypingWithOptionalProperties.ts, 8, 3))
>f : Symbol(f, Decl(subtypingWithOptionalProperties.ts, 0, 0))
>s : Symbol(s, Decl(subtypingWithOptionalProperties.ts, 8, 11))
>Object : Symbol(Object, Decl(lib.d.ts, 92, 1), Decl(lib.d.ts, 223, 11))

r.s && r.s.toFixed(); // would blow up at runtime
>r.s : Symbol(s, Decl(subtypingWithOptionalProperties.ts, 4, 12))
>r : Symbol(r, Decl(subtypingWithOptionalProperties.ts, 8, 3))
>s : Symbol(s, Decl(subtypingWithOptionalProperties.ts, 4, 12))
>r.s.toFixed : Symbol(Number.toFixed, Decl(lib.d.ts, 463, 37))
>r.s : Symbol(s, Decl(subtypingWithOptionalProperties.ts, 4, 12))
>r : Symbol(r, Decl(subtypingWithOptionalProperties.ts, 8, 3))
>s : Symbol(s, Decl(subtypingWithOptionalProperties.ts, 4, 12))
>toFixed : Symbol(Number.toFixed, Decl(lib.d.ts, 463, 37))