Primitives SKIP RUN MAKE_TUPLE DEFINE ASSIGN CAPABILITY Expression operators LENGTH PLUS MINUS TIMES DIV MODULO Match operators LESS_THAN LESS_EQUAL GREATER_THAN GREATER_EQUAL EQUAL NOT_EQUAL MATCH Type tests DATA INT DOUBLE CHAR STREAM Implication stuff IMPLIES DEFAULT GUARD_INFIX_OP GUARD_CALL GUARD_TYPE_TEST Pieces of terms STRING_CONST INTEGER_CONST DOUBLE_CONST TUPLE VAR EXP Variables whose values should be interpolated into a quoted block INTERP_VAR Composition operators and other "flow of control" PAR_COMP SEQ_COMP CHOICE_COMP USER_DEF_COMP BLOCK CALL DIRECTIVE IN OVER PRIM PROGRAM COLON CURRENT_MODULE