29 lines
543 B
Text
29 lines
543 B
Text
example (p q : Prop) : p ∧ q ↔ q ∧ p :=
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begin
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apply iff.intro,
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begin
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intro H,
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apply and.intro,
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apply (and.elim_right H),
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apply (and.elim_left H)
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end,
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begin
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intro H,
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apply and.intro,
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apply (and.elim_right H),
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apply (and.elim_left H)
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end
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end
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example (p q : Prop) : p ∧ q ↔ q ∧ p :=
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begin
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apply iff.intro,
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{intro H,
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apply and.intro,
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apply (and.elim_right H),
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apply (and.elim_left H)},
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{intro H,
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apply and.intro,
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apply (and.elim_right H),
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apply (and.elim_left H)}
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end
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