let X, Y be set ; for f, g being PartFunc of X,Y st TotFuncs f meets TotFuncs g holds
f tolerates g
let f, g be PartFunc of X,Y; ( TotFuncs f meets TotFuncs g implies f tolerates g )
consider h being Element of (TotFuncs f) /\ (TotFuncs g);
assume A1:
(TotFuncs f) /\ (TotFuncs g) <> {}
; XBOOLE_0:def 7 f tolerates g
then A2:
h in TotFuncs f
by XBOOLE_0:def 4;
A3:
h in TotFuncs g
by A1, XBOOLE_0:def 4;
reconsider h = h as PartFunc of X,Y by A2, Th168;
A4:
g tolerates h
by A3, Th171;
f tolerates h
by A2, Th171;
hence
f tolerates g
by A2, A4, Th158, Th169; verum