let k be Element of NAT ; :: thesis: for P being QC-pred_symbol of k
for l being QC-variable_list of holds still_not-bound_in (P ! l) = still_not-bound_in l
let P be QC-pred_symbol of k; :: thesis: for l being QC-variable_list of holds still_not-bound_in (P ! l) = still_not-bound_in l
let l be QC-variable_list of ; :: thesis: still_not-bound_in (P ! l) = still_not-bound_in l
A1: P ! l is atomic by QC_LANG1:def 17;
then the_arguments_of (P ! l) = l by QC_LANG1:def 22;
hence still_not-bound_in (P ! l) = still_not-bound_in l by A1, Th8; :: thesis: verum