Description: Exchange property for span of a pair. TODO: see if a version with Y,Z and X,Z reversed will shorten proofs (analogous to lspexchn1 versus lspexchn2 ); look for lspexch and prcom in same proof. TODO: would a hypothesis of -. X e. ( N{ Z } ) instead of ( N{ X } ) =/= ( N{ Z } ) be better overall? This would be shorter and also satisfy the X =/= .0. condition. Here and also lspindp* and all proofs affected by them (all in NM's mathbox); there are 58 hypotheses with the =/= pattern as of 24-May-2015. (Contributed by NM, 11-Apr-2015)
Ref | Expression | ||
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Hypotheses | lspexch.v | |
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lspexch.o | |
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lspexch.n | |
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lspexch.w | |
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lspexch.x | |
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lspexch.y | |
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lspexch.z | |
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lspexch.q | |
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lspexch.e | |
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Assertion | lspexch | |