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35 lines
392 B
Plaintext
35 lines
392 B
Plaintext
import NNG.Metadata
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import NNG.MyNat.Addition
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import Std.Tactic.RCases
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Game "NNG"
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World "AdvProposition"
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Level 5
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Title ""
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open MyNat
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Introduction
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"
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"
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Statement iff_trans
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""
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(P Q R : Prop) : (P ↔ Q) → (Q ↔ R) → (P ↔ R) := by
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intro hpq hqr
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constructor
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intro p
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apply hqr.1
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apply hpq.1
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assumption
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intro r
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apply hpq.2
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apply hqr.2
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assumption
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Conclusion
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"
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"
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