DEFINE LOGICAL

        [SIC\]DEFINE LOGICAL Var1[DIM1] Var2[DIM2] [...]

    LOGICAL variables can be multi-dimensional. Up to 4  dimensions  can  be
    specified in the optional DIM field, with the following syntax:
        Var[n1] or Var[n1,n2] etc... up to Var[n1,n2,n3,n4]
    where Var is the variable name and n1 to n4  are  integer  constants  or
    variables.