xBeta has a simple if-then statement of the form

%if BooleanExp %then%
   Body

If BooleanExp evaluates to True, then Body is executed

Example

%if a < b %then%
   a := a + b

Other control structures

Other control structures are defined in the qBeta library and defined as keyword patterns

%if BooleanExp %then%
   ThenBody
   %else%
   ElseBody

...