author | wenzelm |
Fri, 28 May 1999 13:30:59 +0200 | |
changeset 6746 | cf6ad8d22793 |
parent 6493 | 3489490c948d |
child 6854 | 60a5ee0ca81d |
permissions | -rw-r--r-- |
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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(* Title: HOL/Isar_examples/Peirce.thy |
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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ID: $Id$ |
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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Author: Markus Wenzel, TU Muenchen |
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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*) |
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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|
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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theory Peirce = Main:; |
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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text {* Peirce's law: examples of classical proof. *}; |
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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theorem "((A --> B) --> A) --> A"; |
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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proof; |
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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assume ABA: "(A --> B) --> A"; |
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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show A; |
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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proof (rule classical); |
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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assume notA: "~ A"; |
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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|
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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have AB: "A --> B"; |
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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proof; |
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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assume A: A; |
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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from notA A; show B; ..; |
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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qed; |
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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from ABA AB; show A; ..; |
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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qed; |
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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qed; |
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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theorem "((A --> B) --> A) --> A"; |
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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proof; |
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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assume ABA: "(A --> B) --> A"; |
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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show A; |
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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proof (rule classical); |
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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|
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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assume AB: "A --> B"; |
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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from ABA AB; show A; ..; |
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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|
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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next; |
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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assume notA: "~ A"; |
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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show "A --> B"; |
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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proof; |
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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assume A: A; |
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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from notA A; show B; ..; |
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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qed; |
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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qed; |
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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qed; |
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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Miscellaneous Isabelle/Isar examples for Higher-Order Logic.
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end; |