24 lines
595 B
Text
24 lines
595 B
Text
open tactic
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#check
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λ (A : Type) (a b c d : A) (H1 : a = b) (H2 : c = b) (H3 : d = c),
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have Hac : a = c, by do {
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h ← get_local `H2,
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hs ← mk_app `eq.symm [h],
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x ← to_expr ```(eq.trans H1 %%hs),
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exact x },
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show a = d, by do {
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x ← to_expr ```(
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have aux : a = c, from Hac,
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have c = d, by do { symmetry, assumption },
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show a = d, by do {
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get_local `Hac >>= clear,
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get_local `H1 >>= clear,
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trace "NESTED CALL:",
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trace_state,
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transitivity,
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get_local `aux >>= exact,
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assumption }),
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trace "-----------",
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trace_state,
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exact x }
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