let x, y be object ; :: thesis: for E being non empty set
for u, v being Element of E ^omega
for F being Subset of (E ^omega)
for TS being non empty transition-system over F
for P being RedSequence of ==>.-relation TS
for k being Nat st k in dom P & k + 1 in dom P & P . k = [x,u] & P . (k + 1) = [y,v] holds
ex w being Element of E ^omega st
( x,w -->. y,TS & u = w ^ v )

let E be non empty set ; :: thesis: for u, v being Element of E ^omega
for F being Subset of (E ^omega)
for TS being non empty transition-system over F
for P being RedSequence of ==>.-relation TS
for k being Nat st k in dom P & k + 1 in dom P & P . k = [x,u] & P . (k + 1) = [y,v] holds
ex w being Element of E ^omega st
( x,w -->. y,TS & u = w ^ v )

let u, v be Element of E ^omega ; :: thesis: for F being Subset of (E ^omega)
for TS being non empty transition-system over F
for P being RedSequence of ==>.-relation TS
for k being Nat st k in dom P & k + 1 in dom P & P . k = [x,u] & P . (k + 1) = [y,v] holds
ex w being Element of E ^omega st
( x,w -->. y,TS & u = w ^ v )

let F be Subset of (E ^omega); :: thesis: for TS being non empty transition-system over F
for P being RedSequence of ==>.-relation TS
for k being Nat st k in dom P & k + 1 in dom P & P . k = [x,u] & P . (k + 1) = [y,v] holds
ex w being Element of E ^omega st
( x,w -->. y,TS & u = w ^ v )

let TS be non empty transition-system over F; :: thesis: for P being RedSequence of ==>.-relation TS
for k being Nat st k in dom P & k + 1 in dom P & P . k = [x,u] & P . (k + 1) = [y,v] holds
ex w being Element of E ^omega st
( x,w -->. y,TS & u = w ^ v )

let P be RedSequence of ==>.-relation TS; :: thesis: for k being Nat st k in dom P & k + 1 in dom P & P . k = [x,u] & P . (k + 1) = [y,v] holds
ex w being Element of E ^omega st
( x,w -->. y,TS & u = w ^ v )

let k be Nat; :: thesis: ( k in dom P & k + 1 in dom P & P . k = [x,u] & P . (k + 1) = [y,v] implies ex w being Element of E ^omega st
( x,w -->. y,TS & u = w ^ v ) )

assume ( k in dom P & k + 1 in dom P & P . k = [x,u] & P . (k + 1) = [y,v] ) ; :: thesis: ex w being Element of E ^omega st
( x,w -->. y,TS & u = w ^ v )

then [[x,u],[y,v]] in ==>.-relation TS by REWRITE1:def 2;
hence ex w being Element of E ^omega st
( x,w -->. y,TS & u = w ^ v ) by Th36; :: thesis: verum