The check-box object resembles a predicate. If the box is checked, it returns "true". If not, it returns "nil". Hence, it can be used as a "switch on / off condition" for the execution of programs. It must be associated with conditional boxes that will call the programs.
![]() | The check-box object has one input and one output :
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To change the box's statement :
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Wherever the box is clicked, it is successively checked or unchecked. Depending on its state, the box output returns "t" or "nil". | ![]() In the first case, the OMIF box returns the second argument, because the checkbox returns "nil". In the second case, it returns the first argument, because the checkbox returns "t". |