
-Result tent_is +Expression

   Eagerly evaulate Expression using tentative assignments.

Arguments
   Result              Variable
   Expression          Arithematic Expression

Type
   library(repair)

Description

This is similar to the normal arithmetic is/2 predicate, but 
evaluates the expression based on the tentative
assignment of its variables. The result is delivered as (an update to)
the tentative value of the Result variable.
Once initiated, tent_is will stay active and keep updating Result's
tentative value eagerly whenever the tentative assignment of any
variable in Expression changes.



See Also
   is / 2, tent_set / 2, tent_call / 3
