if <expr> then <body> [elseif <expr> then <body>]* [else <body>] endThe expressions must be of type "bool". They are evaluated successively until one is found to be true. The body corresponding to the first true expression is executed, and the execution of the if statement then terminates. If none of the expressions is true, the body in the else clause is executed (if the else clause is present). The elseif form provides a convenient way to write a multiway branch.