lean2/tests/lean/show1.lean
Leonardo de Moura e51c4ad2e9 feat(frontends/lean): rename 'using' command to 'open'
Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
2014-09-03 16:00:38 -07:00

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import logic
open bool eq_ops tactic
variables a b c : bool
axiom H1 : a = b
axiom H2 : b = c
check show a = c, from H1 ⬝ H2
print "------------"
check have e1 [fact] : a = b, from H1,
have e2 : a = c, by apply trans; apply e1; apply H2,
have e3 : c = a, from e2⁻¹,
have e4 [fact] : b = a, from e1⁻¹,
show b = c, from e1⁻¹ ⬝ e2