16 lines
166 B
Plaintext
16 lines
166 B
Plaintext
(A/\B)->(A->C)->(B->D)->(C/\D)
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intro et.
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intro i1.
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intro i2.
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split.
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apply i1.
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elim et.
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intro a.
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intro b.
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assumption.
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apply i2.
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elim et.
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intro a.
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intro b.
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assumption.
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