lean2/tests/lean/eq1.lean.expected.out

  Set: pp::colors
  Set: pp::unicode
  Assumed: i
i = 0 : Bool
  Set: lean::pp::coercion
i = (nat_to_int 0) : Bool
refactor(equality): make homogeneous equality the default equality It was not a good idea to use heterogeneous equality as the default equality in Lean. It creates the following problems. - Heterogeneous equality does not propagate constraints in the elaborator. For example, suppose that l has type (List Int), then the expression l = nil will not propagate the type (List Int) to nil. - It is easy to write false. For example, suppose x has type Real, and the user writes x = 0. This is equivalent to false, since 0 has type Nat. The elaborator cannot introduce the coercion since x = 0 is a type correct expression. Homogeneous equality does not suffer from the problems above. We keep heterogeneous equality because it is useful for generating proof terms. Signed-off-by: Leonardo de Moura <leonardo@microsoft.com> 2013-10-29 23:20:02 +00:00			`Set: pp::colors`
			`Set: pp::unicode`
			`Assumed: i`
			`i = 0 : Bool`
			`Set: lean::pp::coercion`
			`i = (nat_to_int 0) : Bool`