SPC
Version 0.9.5

Comparing two expressions forms a condition.
A condition may be negated with the logical negation operator, or two conditions combined with the logical AND and logical OR operators. Like most modern computer languages, SPC supports something called "shortcircuit" evaluation of conditions. This means that if the entire value of the conditional can be logically determined by only evaluating the left hand term of the condition, then the right hand term will not be evaluated.
The table below summarizes the different types of conditions.
Condition  Meaning 

Expr  true if expr is not equal to 0 
Expr1 == expr2  true if expr1 equals expr2 
Expr1 != expr2  true if expr1 is not equal to expr2 
Expr1 < expr2  true if one expr1 is less than expr2 
Expr1 <= expr2  true if expr1 is less than or equal to expr2 
Expr1 > expr2  true if expr1 is greater than expr2 
Expr1 >= expr2  true if expr1 is greater than or equal to expr2 
! condition  logical negation of a condition  true if condition is false 
Cond1 && cond2  logical AND of two conditions (true if and only if both conditions are true) 
Cond1  cond2  logical OR of two conditions (true if and only if at least one of the conditions are true) 
There are also two special constant conditions which can be used anywhere that the above conditions are allowed. They are listed below.
You can use conditions in SPC control structures, such as the ifstatement and the while or until statements, to specify exactly how you want your program to behave.