.he 'ISREAL''Page %'
.fo 'Steven Hardy''January 78'
ISREAL	This function returns TRUE if its argument is a 'real` number, for example:
 	: ISREAL(3.4) =>
 	** <TRUE>
 	: ISREAL(SQRT(10)) =>
 	** <TRUE>
 	: ISREAL(3) =>
 	** <FALSE>
.br
ISREAL could be defined thus:
 	: FUNCTION ISREAL(OBJ);
 	:	DATAWORD(OBJ) = "REAL"
 	: END;
