Check and evaluate an expression.
eval expression
The eval command evaluates an expression and prints the result as a number.
gnucap> param a={b+c+7}
gnucap> eval a
parameter b+c+7 has no value
parameter b+c+7 has no value
a= NA
gnucap> param b=c+3
gnucap> param c=4
gnucap> eval a
a= 18.
gnucap> eval b+c
(b + c)= 11.
gnucap>