lean4-htt/tests/lean/show1.lean
2016-07-31 12:50:11 -07:00

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Text

import logic
open bool eq tactic
notation H `⁻¹` := symm H --input with \sy or \-1 or \inv
notation H1 ⬝ H2 := trans H1 H2
constants a b c : bool
axiom H1 : a = b
axiom H2 : b = c
check show a = c, from H1 ⬝ H2
print "------------"
check have e1 : a = b, from H1,
have e2 : a = c, from sorry, -- by apply eq.trans; apply e1; apply H2,
have e3 : c = a, from e2⁻¹,
have e4 : b = a, from e1⁻¹,
show b = c, from e1⁻¹ ⬝ e2