let X be set ; for p, q being XFinSequence
for n being Element of NAT st Shift ((p ^ q),n) c= X holds
Shift (p,n) c= X
let p, q be XFinSequence; for n being Element of NAT st Shift ((p ^ q),n) c= X holds
Shift (p,n) c= X
let n be Element of NAT ; ( Shift ((p ^ q),n) c= X implies Shift (p,n) c= X )
assume A1:
Shift ((p ^ q),n) c= X
; Shift (p,n) c= X
Shift (p,n) c= Shift ((p ^ q),n)
by Th84;
hence
Shift (p,n) c= X
by A1, XBOOLE_1:1; verum