let P be the Instructions of SCMPDS -valued ManySortedSet of NAT ; for s being State of SCMPDS st P halts_on s holds
for k being Element of NAT st LifeSpan (P,s) <= k holds
CurInstr (P,(Comput (P,s,k))) = halt SCMPDS
let s be State of SCMPDS; ( P halts_on s implies for k being Element of NAT st LifeSpan (P,s) <= k holds
CurInstr (P,(Comput (P,s,k))) = halt SCMPDS )
assume
P halts_on s
; for k being Element of NAT st LifeSpan (P,s) <= k holds
CurInstr (P,(Comput (P,s,k))) = halt SCMPDS
then A1:
CurInstr (P,(Comput (P,s,(LifeSpan (P,s))))) = halt SCMPDS
by EXTPRO_1:def 14;
let k be Element of NAT ; ( LifeSpan (P,s) <= k implies CurInstr (P,(Comput (P,s,k))) = halt SCMPDS )
assume
LifeSpan (P,s) <= k
; CurInstr (P,(Comput (P,s,k))) = halt SCMPDS
then
Comput (P,s,(LifeSpan (P,s))) = Comput (P,s,k)
by A1, EXTPRO_1:6;
hence
CurInstr (P,(Comput (P,s,k))) = halt SCMPDS
by A1; verum