lean2/tests/lean/subst3.lean
Leonardo de Moura 935c2a03a3 feat(*): change name conventions for Lean builtin libraries
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2014-01-05 19:21:44 -08:00

7 lines
No EOL
246 B
Text

import macros
theorem T (A : Type) (p : A -> Bool) (f : A -> A -> A) : forall x y z, p (f x x) => x = y => x = z => p (f y z) :=
take x y z, assume (H1 : p (f x x)) (H2 : x = y) (H3 : x = z),
subst (subst H1 H2) H3
print environment 1.