13 lines
240 B
Text
13 lines
240 B
Text
import tactic.
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variables a b c d e : Bool.
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axiom H1 : a => b.
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axiom H2 : b = c.
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axiom H3 : c => d.
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axiom H4 : d <=> e.
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theorem T : a => e
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:= calc a => b : H1
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... = c : H2
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... => d : (by apply H3)
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... <=> e : H4.
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