let s be State of SCM ; ( Euclide-Algorithm c= s implies for k being Element of NAT st IC (Comput (ProgramPart s),s,k) = 2 holds
( IC (Comput (ProgramPart s),s,(k + 1)) = 3 & (Comput (ProgramPart s),s,(k + 1)) . (dl. 0 ) = (Comput (ProgramPart s),s,k) . (dl. 2) & (Comput (ProgramPart s),s,(k + 1)) . (dl. 1) = (Comput (ProgramPart s),s,k) . (dl. 1) & (Comput (ProgramPart s),s,(k + 1)) . (dl. 2) = (Comput (ProgramPart s),s,k) . (dl. 2) ) )
assume A1:
Euclide-Algorithm c= s
; for k being Element of NAT st IC (Comput (ProgramPart s),s,k) = 2 holds
( IC (Comput (ProgramPart s),s,(k + 1)) = 3 & (Comput (ProgramPart s),s,(k + 1)) . (dl. 0 ) = (Comput (ProgramPart s),s,k) . (dl. 2) & (Comput (ProgramPart s),s,(k + 1)) . (dl. 1) = (Comput (ProgramPart s),s,k) . (dl. 1) & (Comput (ProgramPart s),s,(k + 1)) . (dl. 2) = (Comput (ProgramPart s),s,k) . (dl. 2) )
let k be Element of NAT ; ( IC (Comput (ProgramPart s),s,k) = 2 implies ( IC (Comput (ProgramPart s),s,(k + 1)) = 3 & (Comput (ProgramPart s),s,(k + 1)) . (dl. 0 ) = (Comput (ProgramPart s),s,k) . (dl. 2) & (Comput (ProgramPart s),s,(k + 1)) . (dl. 1) = (Comput (ProgramPart s),s,k) . (dl. 1) & (Comput (ProgramPart s),s,(k + 1)) . (dl. 2) = (Comput (ProgramPart s),s,k) . (dl. 2) ) )
assume A2:
IC (Comput (ProgramPart s),s,k) = 2
; ( IC (Comput (ProgramPart s),s,(k + 1)) = 3 & (Comput (ProgramPart s),s,(k + 1)) . (dl. 0 ) = (Comput (ProgramPart s),s,k) . (dl. 2) & (Comput (ProgramPart s),s,(k + 1)) . (dl. 1) = (Comput (ProgramPart s),s,k) . (dl. 1) & (Comput (ProgramPart s),s,(k + 1)) . (dl. 2) = (Comput (ProgramPart s),s,k) . (dl. 2) )
A3: Comput (ProgramPart s),s,(k + 1) =
Exec (s . (IC (Comput (ProgramPart s),s,k))),(Comput (ProgramPart s),s,k)
by AMI_1:55
.=
Exec ((dl. 0 ) := (dl. 2)),(Comput (ProgramPart s),s,k)
by A1, A2, Lm3
;
hence IC (Comput (ProgramPart s),s,(k + 1)) =
succ (IC (Comput (ProgramPart s),s,k))
by AMI_3:8
.=
2 + 1
by A2
.=
3
;
( (Comput (ProgramPart s),s,(k + 1)) . (dl. 0 ) = (Comput (ProgramPart s),s,k) . (dl. 2) & (Comput (ProgramPart s),s,(k + 1)) . (dl. 1) = (Comput (ProgramPart s),s,k) . (dl. 1) & (Comput (ProgramPart s),s,(k + 1)) . (dl. 2) = (Comput (ProgramPart s),s,k) . (dl. 2) )
thus
(Comput (ProgramPart s),s,(k + 1)) . (dl. 0 ) = (Comput (ProgramPart s),s,k) . (dl. 2)
by A3, AMI_3:8; ( (Comput (ProgramPart s),s,(k + 1)) . (dl. 1) = (Comput (ProgramPart s),s,k) . (dl. 1) & (Comput (ProgramPart s),s,(k + 1)) . (dl. 2) = (Comput (ProgramPart s),s,k) . (dl. 2) )
thus
( (Comput (ProgramPart s),s,(k + 1)) . (dl. 1) = (Comput (ProgramPart s),s,k) . (dl. 1) & (Comput (ProgramPart s),s,(k + 1)) . (dl. 2) = (Comput (ProgramPart s),s,k) . (dl. 2) )
by A3, AMI_3:8, AMI_3:52; verum