let R be Ring; :: thesis: for a, b being Data-Location of R holds not a := b is halting
let a, b be Data-Location of R; :: thesis: not a := b is halting
set s = the State of (SCM R);
(Exec ((a := b), the State of (SCM R))) . (IC ) = (IC the State of (SCM R)) + 1 by Th11;
hence not a := b is halting by Th18; :: thesis: verum