LET Free_Syntax

        The LET command may be omitted if no option is present, and  if  the
    SIC  syntax  is  set to FREE. In this case, the = sign is mandatory.  In
    FIXED syntax, the LET command is compulsory, but the = sign optional. In
    FREE syntax, commands lines like
           A[I,J] = SIN((2*I+J)/PI)
    where A is a known variable, are recognized as assignement and automati-
    cally expanded to the equivalent FIXED syntax
           LET A[I,J] SIN((2*I+J)/PI)
    In case  of conflict between a variable name and  a  (complete)  command
    name,  an  error  message  is issued. Free syntax cannot be used for the
    LET /WHERE command. Command SIC SYNTAX [Free|Fixed] can be used to  tog-
    gle between Fixed and Free syntax if needed.