theorem Th99:
for
A being
preIfWhileAlgebra for
C,
I being
Element of
A for
S being non
empty set for
T being
Subset of
S for
s being
Element of
S for
f being
ExecutionFunction of
A,
S,
T st
A is
free &
[s,(while (C,I))] in TerminatingPrograms (
A,
S,
T,
f) holds
(
[s,C] in TerminatingPrograms (
A,
S,
T,
f) & ex
r being non
empty FinSequence of
S st
(
r . 1
= f . (
s,
C) &
r . (len r) nin T & ( for
i being
Nat st 1
<= i &
i < len r holds
(
r . i in T &
[(r . i),(I \; C)] in TerminatingPrograms (
A,
S,
T,
f) &
r . (i + 1) = f . (
(r . i),
(I \; C)) ) ) ) )