9 lines
199 B
Text
9 lines
199 B
Text
import standard
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using tactic
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theorem tst (a b : Bool) (H : a ↔ b) : b ↔ a
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:= by apply iff_intro;
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⟦ assume Hb, iff_mp_right H Hb ⟧;
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⟦ assume Ha, iff_mp_left H Ha ⟧
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check tst
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