FOR(init. ; condition ; reinit.)
init. specifies the initial value of the loop counter or any other variable
used in the statement block. If no initialization is required this code may be
condition specifies the looping condition. The statement block
is executed if
the condition (which must have a relational operator construct) is true. If the
condition is false, looping is stopped and the statement following the
statement block is executed. This code may be void.
reinit. specifies the code executed after each pass through the
statement block and before the condition is tested. This code may be void.
FOR(I=1;I<=100;I=I+1) A(I)=0.# same as DO loop