let s be State of SCMPDS ; for I being Program of SCMPDS
for a, b being Int_position
for i being Integer st s . (DataLoc (s . a),i) >= 0 holds
(IExec (while<0 a,i,I),s) . b = s . b
let I be Program of SCMPDS ; for a, b being Int_position
for i being Integer st s . (DataLoc (s . a),i) >= 0 holds
(IExec (while<0 a,i,I),s) . b = s . b
let a, b be Int_position ; for i being Integer st s . (DataLoc (s . a),i) >= 0 holds
(IExec (while<0 a,i,I),s) . b = s . b
let i be Integer; ( s . (DataLoc (s . a),i) >= 0 implies (IExec (while<0 a,i,I),s) . b = s . b )
assume
s . (DataLoc (s . a),i) >= 0
; (IExec (while<0 a,i,I),s) . b = s . b
then A1:
IExec (while<0 a,i,I),s = s +* (Start-At ((card I) + 2),SCMPDS )
by Th10;
not b in dom (Start-At ((card I) + 2),SCMPDS )
by SCMPDS_4:59;
hence
(IExec (while<0 a,i,I),s) . b = s . b
by A1, FUNCT_4:12; verum