where
The word "where" is often used in mathematical expressions
to set variables or to say side conditions.
CDname logic1.implies can be used for these purposes, but
"where" will be more intuitive and more friendly expression
for formula book writers.
$ x^n \mbox{where} n=10
OMLBIND(OMBVAR(n), x ~arith1.power~ n)
~logic1p.where~ (n ~relation1.eq~ 10);