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Metamath Proof Explorer

Theorem pm5.11

Description: Theorem *5.11 of WhiteheadRussell p. 123. (Contributed by NM, 3-Jan-2005)

Ref Expression
Assertion pm5.11 
|- ( ( ph -> ps ) \/ ( -. ph -> ps ) )

Proof

Step Hyp Ref Expression
1 pm5.11g 
 |-  ( ( ph -> ps ) \/ ( -. ph -> ps ) )