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Mirrors > Home > MPE Home > Th. List > mptnan | Structured version Visualization version Unicode version |
Description: Modus ponendo tollens 1, one of the "indemonstrables" in Stoic logic. See rule 1 on [Lopez-Astorga] p. 12 , rule 1 on [Sanford] p. 40, and rule A3 in [Hitchcock] p. 5. Sanford describes this rule second (after mptxor 1694) as a "safer, and these days much more common" version of modus ponendo tollens because it avoids confusion between inclusive-or and exclusive-or. (Contributed by David A. Wheeler, 3-Jul-2016.) |
Ref | Expression |
---|---|
mptnan.min | |
mptnan.maj |
Ref | Expression |
---|---|
mptnan |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | mptnan.min | . 2 | |
2 | mptnan.maj | . . 3 | |
3 | 2 | imnani 439 | . 2 |
4 | 1, 3 | ax-mp 5 | 1 |
Colors of variables: wff setvar class |
Syntax hints: wn 3 wa 384 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 |
This theorem depends on definitions: df-bi 197 df-an 386 |
This theorem is referenced by: mptxor 1694 alephsucpw2 8934 aleph1re 14974 |
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