let A be Euclidean preIfWhileAlgebra; for X being non empty countable set
for s being Element of Funcs X,INT
for T being Subset of (Funcs X,INT )
for f being Euclidean ExecutionFunction of A, Funcs X,INT ,T
for x, y being Variable of f holds
( (f . s,(x *= y)) . x = (s . x) * (s . y) & ( for z being Element of X st z <> x holds
(f . s,(x *= y)) . z = s . z ) )
let X be non empty countable set ; for s being Element of Funcs X,INT
for T being Subset of (Funcs X,INT )
for f being Euclidean ExecutionFunction of A, Funcs X,INT ,T
for x, y being Variable of f holds
( (f . s,(x *= y)) . x = (s . x) * (s . y) & ( for z being Element of X st z <> x holds
(f . s,(x *= y)) . z = s . z ) )
let s be Element of Funcs X,INT ; for T being Subset of (Funcs X,INT )
for f being Euclidean ExecutionFunction of A, Funcs X,INT ,T
for x, y being Variable of f holds
( (f . s,(x *= y)) . x = (s . x) * (s . y) & ( for z being Element of X st z <> x holds
(f . s,(x *= y)) . z = s . z ) )
let T be Subset of (Funcs X,INT ); for f being Euclidean ExecutionFunction of A, Funcs X,INT ,T
for x, y being Variable of f holds
( (f . s,(x *= y)) . x = (s . x) * (s . y) & ( for z being Element of X st z <> x holds
(f . s,(x *= y)) . z = s . z ) )
let f be Euclidean ExecutionFunction of A, Funcs X,INT ,T; for x, y being Variable of f holds
( (f . s,(x *= y)) . x = (s . x) * (s . y) & ( for z being Element of X st z <> x holds
(f . s,(x *= y)) . z = s . z ) )
let x, y be Variable of f; ( (f . s,(x *= y)) . x = (s . x) * (s . y) & ( for z being Element of X st z <> x holds
(f . s,(x *= y)) . z = s . z ) )
A1:
dom ((. x) (#) (. y)) = Funcs X,INT
by FUNCT_2:def 1;
(^ x) . s = x
by FUNCOP_1:13;
hence (f . s,(x *= y)) . x =
((. x) (#) (. y)) . s
by Th24
.=
((. x) . s) * ((. y) . s)
by A1, VALUED_1:def 4
.=
(s . x) * ((. y) . s)
by Th22
.=
(s . x) * (s . y)
by Th22
;
for z being Element of X st z <> x holds
(f . s,(x *= y)) . z = s . z
thus
for z being Element of X st z <> x holds
(f . s,(x *= y)) . z = s . z
by Th26; verum