let A be Euclidean preIfWhileAlgebra; for X being non empty countable set
for T being Subset of (Funcs X,INT )
for f being Euclidean ExecutionFunction of A, Funcs X,INT ,T
for t being INT-Expression of A,f
for b being Element of X
for g being Euclidean ExecutionFunction of A, Funcs X,INT ,(Funcs X,INT ) \ b,0
for P being set
for I being Element of A st I is_terminating_wrt g,P holds
for i, n being Variable of g st ex d being Function st
( d . b = 0 & d . n = 1 & d . i = 2 ) & ( for s being Element of Funcs X,INT st s in P holds
( (g . s,I) . n = s . n & (g . s,I) . i = s . i ) ) & P is_invariant_wrt i := t,g & P is_invariant_wrt I,g & P is_invariant_wrt i leq n,g & P is_invariant_wrt i += 1,g holds
for-do (i := t),(i leq n),(i += 1),I is_terminating_wrt g,P
let X be non empty countable set ; for T being Subset of (Funcs X,INT )
for f being Euclidean ExecutionFunction of A, Funcs X,INT ,T
for t being INT-Expression of A,f
for b being Element of X
for g being Euclidean ExecutionFunction of A, Funcs X,INT ,(Funcs X,INT ) \ b,0
for P being set
for I being Element of A st I is_terminating_wrt g,P holds
for i, n being Variable of g st ex d being Function st
( d . b = 0 & d . n = 1 & d . i = 2 ) & ( for s being Element of Funcs X,INT st s in P holds
( (g . s,I) . n = s . n & (g . s,I) . i = s . i ) ) & P is_invariant_wrt i := t,g & P is_invariant_wrt I,g & P is_invariant_wrt i leq n,g & P is_invariant_wrt i += 1,g holds
for-do (i := t),(i leq n),(i += 1),I is_terminating_wrt g,P
let T be Subset of (Funcs X,INT ); for f being Euclidean ExecutionFunction of A, Funcs X,INT ,T
for t being INT-Expression of A,f
for b being Element of X
for g being Euclidean ExecutionFunction of A, Funcs X,INT ,(Funcs X,INT ) \ b,0
for P being set
for I being Element of A st I is_terminating_wrt g,P holds
for i, n being Variable of g st ex d being Function st
( d . b = 0 & d . n = 1 & d . i = 2 ) & ( for s being Element of Funcs X,INT st s in P holds
( (g . s,I) . n = s . n & (g . s,I) . i = s . i ) ) & P is_invariant_wrt i := t,g & P is_invariant_wrt I,g & P is_invariant_wrt i leq n,g & P is_invariant_wrt i += 1,g holds
for-do (i := t),(i leq n),(i += 1),I is_terminating_wrt g,P
let f be Euclidean ExecutionFunction of A, Funcs X,INT ,T; for t being INT-Expression of A,f
for b being Element of X
for g being Euclidean ExecutionFunction of A, Funcs X,INT ,(Funcs X,INT ) \ b,0
for P being set
for I being Element of A st I is_terminating_wrt g,P holds
for i, n being Variable of g st ex d being Function st
( d . b = 0 & d . n = 1 & d . i = 2 ) & ( for s being Element of Funcs X,INT st s in P holds
( (g . s,I) . n = s . n & (g . s,I) . i = s . i ) ) & P is_invariant_wrt i := t,g & P is_invariant_wrt I,g & P is_invariant_wrt i leq n,g & P is_invariant_wrt i += 1,g holds
for-do (i := t),(i leq n),(i += 1),I is_terminating_wrt g,P
let t be INT-Expression of A,f; for b being Element of X
for g being Euclidean ExecutionFunction of A, Funcs X,INT ,(Funcs X,INT ) \ b,0
for P being set
for I being Element of A st I is_terminating_wrt g,P holds
for i, n being Variable of g st ex d being Function st
( d . b = 0 & d . n = 1 & d . i = 2 ) & ( for s being Element of Funcs X,INT st s in P holds
( (g . s,I) . n = s . n & (g . s,I) . i = s . i ) ) & P is_invariant_wrt i := t,g & P is_invariant_wrt I,g & P is_invariant_wrt i leq n,g & P is_invariant_wrt i += 1,g holds
for-do (i := t),(i leq n),(i += 1),I is_terminating_wrt g,P
let b be Element of X; for g being Euclidean ExecutionFunction of A, Funcs X,INT ,(Funcs X,INT ) \ b,0
for P being set
for I being Element of A st I is_terminating_wrt g,P holds
for i, n being Variable of g st ex d being Function st
( d . b = 0 & d . n = 1 & d . i = 2 ) & ( for s being Element of Funcs X,INT st s in P holds
( (g . s,I) . n = s . n & (g . s,I) . i = s . i ) ) & P is_invariant_wrt i := t,g & P is_invariant_wrt I,g & P is_invariant_wrt i leq n,g & P is_invariant_wrt i += 1,g holds
for-do (i := t),(i leq n),(i += 1),I is_terminating_wrt g,P
let g be Euclidean ExecutionFunction of A, Funcs X,INT ,(Funcs X,INT ) \ b,0 ; for P being set
for I being Element of A st I is_terminating_wrt g,P holds
for i, n being Variable of g st ex d being Function st
( d . b = 0 & d . n = 1 & d . i = 2 ) & ( for s being Element of Funcs X,INT st s in P holds
( (g . s,I) . n = s . n & (g . s,I) . i = s . i ) ) & P is_invariant_wrt i := t,g & P is_invariant_wrt I,g & P is_invariant_wrt i leq n,g & P is_invariant_wrt i += 1,g holds
for-do (i := t),(i leq n),(i += 1),I is_terminating_wrt g,P
set Z = Funcs X,INT ;
set T = (Funcs X,INT ) \ b,0 ;
let S be set ; for I being Element of A st I is_terminating_wrt g,S holds
for i, n being Variable of g st ex d being Function st
( d . b = 0 & d . n = 1 & d . i = 2 ) & ( for s being Element of Funcs X,INT st s in S holds
( (g . s,I) . n = s . n & (g . s,I) . i = s . i ) ) & S is_invariant_wrt i := t,g & S is_invariant_wrt I,g & S is_invariant_wrt i leq n,g & S is_invariant_wrt i += 1,g holds
for-do (i := t),(i leq n),(i += 1),I is_terminating_wrt g,S
let I be Element of A; ( I is_terminating_wrt g,S implies for i, n being Variable of g st ex d being Function st
( d . b = 0 & d . n = 1 & d . i = 2 ) & ( for s being Element of Funcs X,INT st s in S holds
( (g . s,I) . n = s . n & (g . s,I) . i = s . i ) ) & S is_invariant_wrt i := t,g & S is_invariant_wrt I,g & S is_invariant_wrt i leq n,g & S is_invariant_wrt i += 1,g holds
for-do (i := t),(i leq n),(i += 1),I is_terminating_wrt g,S )
assume A1:
I is_terminating_wrt g,S
; for i, n being Variable of g st ex d being Function st
( d . b = 0 & d . n = 1 & d . i = 2 ) & ( for s being Element of Funcs X,INT st s in S holds
( (g . s,I) . n = s . n & (g . s,I) . i = s . i ) ) & S is_invariant_wrt i := t,g & S is_invariant_wrt I,g & S is_invariant_wrt i leq n,g & S is_invariant_wrt i += 1,g holds
for-do (i := t),(i leq n),(i += 1),I is_terminating_wrt g,S
let i, n be Variable of g; ( ex d being Function st
( d . b = 0 & d . n = 1 & d . i = 2 ) & ( for s being Element of Funcs X,INT st s in S holds
( (g . s,I) . n = s . n & (g . s,I) . i = s . i ) ) & S is_invariant_wrt i := t,g & S is_invariant_wrt I,g & S is_invariant_wrt i leq n,g & S is_invariant_wrt i += 1,g implies for-do (i := t),(i leq n),(i += 1),I is_terminating_wrt g,S )
given d being Function such that A2:
d . b = 0
and
A3:
d . n = 1
and
A4:
d . i = 2
; ( ex s being Element of Funcs X,INT st
( s in S & not ( (g . s,I) . n = s . n & (g . s,I) . i = s . i ) ) or not S is_invariant_wrt i := t,g or not S is_invariant_wrt I,g or not S is_invariant_wrt i leq n,g or not S is_invariant_wrt i += 1,g or for-do (i := t),(i leq n),(i += 1),I is_terminating_wrt g,S )
set C = i leq n;
set J = I \; (i += 1);
assume that
A5:
for s being Element of Funcs X,INT st s in S holds
( (g . s,I) . n = s . n & (g . s,I) . i = s . i )
and
A6:
S is_invariant_wrt i := t,g
and
A7:
S is_invariant_wrt I,g
and
A8:
S is_invariant_wrt i leq n,g
and
A9:
S is_invariant_wrt i += 1,g
; for-do (i := t),(i leq n),(i += 1),I is_terminating_wrt g,S
let s be Element of Funcs X,INT ; AOFA_000:def 38 ( not s in S or [s,(for-do (i := t),(i leq n),(i += 1),I)] in TerminatingPrograms A,(Funcs X,INT ),((Funcs X,INT ) \ b,0 ),g )
assume
s in S
; [s,(for-do (i := t),(i leq n),(i += 1),I)] in TerminatingPrograms A,(Funcs X,INT ),((Funcs X,INT ) \ b,0 ),g
then A10:
g . s,(i := t) in S
by A6, AOFA_000:def 39;
for s being Element of Funcs X,INT st s in S holds
( (g . s,I) . n = s . n & (g . s,I) . i = s . i & g . s,I in S & g . s,(i leq n) in S & g . s,(i += 1) in S )
by A5, A7, A8, A9, AOFA_000:def 39;
then A11:
g iteration_terminates_for (I \; (i += 1)) \; (i leq n),g . (g . s,(i := t)),(i leq n)
by A2, A3, A4, A10, Th53;
set Q = while (i leq n),(I \; (i += 1));
A12:
i leq n is_terminating_wrt g
by AOFA_000:104;
A13:
[s,(i := t)] in TerminatingPrograms A,(Funcs X,INT ),((Funcs X,INT ) \ b,0 ),g
by AOFA_000:def 36;
S is_invariant_wrt I \; (i += 1),g
by A7, A9, AOFA_000:109;
then A14:
for s being Element of Funcs X,INT st s in S & g . (g . s,(I \; (i += 1))),(i leq n) in (Funcs X,INT ) \ b,0 holds
g . s,(I \; (i += 1)) in S
by AOFA_000:def 39;
i += 1 is_terminating_wrt g,S
by AOFA_000:107;
then
[(g . s,(i := t)),(while (i leq n),(I \; (i += 1)))] in TerminatingPrograms A,(Funcs X,INT ),((Funcs X,INT ) \ b,0 ),g
by A1, A7, A8, A10, A11, A12, A14, AOFA_000:111, AOFA_000:116;
hence
[s,(for-do (i := t),(i leq n),(i += 1),I)] in TerminatingPrograms A,(Funcs X,INT ),((Funcs X,INT ) \ b,0 ),g
by A13, AOFA_000:def 35; verum
set P = for-do (i := t),(i leq n),(i += 1),I;