Simple Conditions
The conditions within an If construct are expressions which evaluate to true or false.
In the simple case, the expression is a constant, variable, or function call. Expressions whose numeric interpretation evaluates to a non-zero value are true. Those which evaluate to zero are false.
Terminal
USER>if 0 {write "true"} USER>if 5 {write "true"} true USER>set condition = "a" USER>if condition {write "true"} USER>set condition = "1000" USER>if condition {write "true"} true USER>set condition = -2 USER>if condition {write "true"} true USER>if $zsqr(64) {write "true"} true USER>