is an option for Trace and related functions that specifies whether symbols such as x should match symbols with local names of the form x$nnn.


  • The default setting is MatchLocalNames->True.
  • With the default setting, Trace[expr,x=rhs] will show assignments to local variables whose names are of the form x$nnn.
  • Trace[expr,x=rhs,MatchLocalNames->False] shows assignments only for the global symbol x.


Basic Examples  (1)

By default, Trace will match local variables:

With MatchLocalNames->False, only an explicit match of x will show up:

Introduced in 1991