Metamath Proof Explorer


Theorem albitr

Description: Theorem *10.301 in WhiteheadRussell p. 151. (Contributed by Andrew Salmon, 24-May-2011)

Ref Expression
Assertion albitr xφψxψχxφχ

Proof

Step Hyp Ref Expression
1 bitr φψψχφχ
2 1 alanimi xφψxψχxφχ