let x, y be set ; for E being non empty set
for e being Element of E
for F being Subset of (E ^omega)
for TS being non empty transition-system over F st x,<%e%> ==>* y, <%> E, _bool TS holds
x,<%e%> ==>. y, <%> E, _bool TS
let E be non empty set ; for e being Element of E
for F being Subset of (E ^omega)
for TS being non empty transition-system over F st x,<%e%> ==>* y, <%> E, _bool TS holds
x,<%e%> ==>. y, <%> E, _bool TS
let e be Element of E; for F being Subset of (E ^omega)
for TS being non empty transition-system over F st x,<%e%> ==>* y, <%> E, _bool TS holds
x,<%e%> ==>. y, <%> E, _bool TS
let F be Subset of (E ^omega); for TS being non empty transition-system over F st x,<%e%> ==>* y, <%> E, _bool TS holds
x,<%e%> ==>. y, <%> E, _bool TS
let TS be non empty transition-system over F; ( x,<%e%> ==>* y, <%> E, _bool TS implies x,<%e%> ==>. y, <%> E, _bool TS )
not <%> E in rng (dom the Tran of (_bool TS))
by REWRITE3:def 1;
hence
( x,<%e%> ==>* y, <%> E, _bool TS implies x,<%e%> ==>. y, <%> E, _bool TS )
by REWRITE3:92; verum