let B be CQC-WFF-like Element of [:QC-Sub-WFF ,bound_QC-variables :]; for SQ being second_Q_comp of B
for B1 being Element of [:QC-Sub-WFF ,bound_QC-variables :]
for SQ1 being second_Q_comp of B1 st B is quantifiable & B1 is quantifiable & CQCSub_All B,SQ = Sub_All B1,SQ1 holds
( B `2 = B1 `2 & SQ = SQ1 )
let SQ be second_Q_comp of B; for B1 being Element of [:QC-Sub-WFF ,bound_QC-variables :]
for SQ1 being second_Q_comp of B1 st B is quantifiable & B1 is quantifiable & CQCSub_All B,SQ = Sub_All B1,SQ1 holds
( B `2 = B1 `2 & SQ = SQ1 )
let B1 be Element of [:QC-Sub-WFF ,bound_QC-variables :]; for SQ1 being second_Q_comp of B1 st B is quantifiable & B1 is quantifiable & CQCSub_All B,SQ = Sub_All B1,SQ1 holds
( B `2 = B1 `2 & SQ = SQ1 )
let SQ1 be second_Q_comp of B1; ( B is quantifiable & B1 is quantifiable & CQCSub_All B,SQ = Sub_All B1,SQ1 implies ( B `2 = B1 `2 & SQ = SQ1 ) )
assume that
A1:
B is quantifiable
and
A2:
B1 is quantifiable
and
A3:
CQCSub_All B,SQ = Sub_All B1,SQ1
; ( B `2 = B1 `2 & SQ = SQ1 )
Sub_All B,SQ = Sub_All B1,SQ1
by A1, A3, Def6;
hence
( B `2 = B1 `2 & SQ = SQ1 )
by A1, A2, Th36; verum