1INCLAN: if - Fortran-77 logical or block if statement

Usage: if (<condition>) <command> {<parameter>}
       if (<condition>) then
         .
         .
       else if (<condition>) then
         .
         .
       else
         .
         .
       end if

The "if" statement allows for Fortran-77 style logical or block if 
statements. A logical "if" statement must not end with the word "then".

Example: if (i.gt.0) then
           print "$i is greater than 0."
         else if (def('x') .and. exist('y')) then
           print "The variable x is defined, and the variable y exists."
         else if (string.ne.' ') then
           print "The variable string has the non-blank value $string."
           if (mod(j,2).eq.1) print "j is odd."
         end if