Logical Expressions

Modula-3 supports the usual boolean operators. Short-circuit (conditional) evaluation is used. From highest to lowest precedence, they are:

NOT <expr>
TRUE if <expr> is FALSE; FALSE if <expr> is TRUE
<expr1> AND <expr2>
TRUE iff <expr1> and <expr2> are both TRUE, otherwise FALSE
<expr1> OR <expr2>
TRUE iff either <expr1> or <expr2> is TRUE, otherwise FALSE

Modula-3 also supports bitwise logical computation on unsigned numbers using the procedures in the Word interface (see section Word Interface).