let A be Euclidean preIfWhileAlgebra; :: thesis: 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 . 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 ; :: thesis: 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 . 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 ; :: thesis: 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 . 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 ); :: thesis: 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 . 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; :: thesis: for x, y being Variable of f holds
( (f . s,(x := y)) . 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; :: thesis: ( (f . s,(x := y)) . x = s . y & ( for z being Element of X st z <> x holds
(f . s,(x := y)) . z = s . z ) )
(. y) . s = s . y by Th22;
hence ( (f . s,(x := y)) . x = s . y & ( for z being Element of X st z <> x holds
(f . s,(x := y)) . z = s . z ) ) by Th26; :: thesis: verum