V=VLREAD()
$(VARIABLE LIST READ. V, A LIST OF VARIABLES, IS READ FROM THE INPUT
STREAM. ANY PRECEDING BLANKS ARE SKIPPED.)
SAFE C.
(1) $(READ VARIABLES.) V=(). C=CREADB(). IF C NE $=( THEN GO TO 2.
C=CREADB(). IF C=$=) THEN RETURN ELSE BKSP. REPEAT
( VL=VREAD(). V=COMP(VL,V). C=CREADB(). IF C=$=) THEN
( V=INV(V). RETURN ) ELSE IF C NE $=, THEN GO TO 2 ).
(2) $(ERROR.) PRINT $(ERROR FOUND BY VLREAD.). DIBUFF. STOP..