let X be Subset of CQC-WFF ; for p, q being Element of CQC-WFF
for x being bound_QC-variable st X |- p => q & not x in still_not-bound_in p holds
X |- p => (All x,q)
let p, q be Element of CQC-WFF ; for x being bound_QC-variable st X |- p => q & not x in still_not-bound_in p holds
X |- p => (All x,q)
let x be bound_QC-variable; ( X |- p => q & not x in still_not-bound_in p implies X |- p => (All x,q) )
assume that
A1:
X |- p => q
and
A2:
not x in still_not-bound_in p
; X |- p => (All x,q)
p => q in Cn X
by A1, Def9;
then
p => (All x,q) in Cn X
by A2, Th34;
hence
X |- p => (All x,q)
by Def9; verum