BEGIN "STRIP"
   REQUIRE "STD.HDR[170,161]" SOURCE!FILE;
   COMMENT TO CHANGE DOUBLE SPACING TO SINGLE SPACING;
   INTEGER INCHAN,OUTCHAN,TEMP,EOF;
   WRITE("INPUT FILE NAME - ");
   INCHAN := OPENIN(INCHWL,EOF);
   WRITE("OUTPUT FILE NAME - ");
   OUTCHAN := OPENOUT(INCHWL);
   WHILE TRUE DO
   BEGIN
      LABEL LAB;
      TEMP := WORDIN(INCHAN);
   LAB:
      IF EOF THEN
	DONE;
      IF TEMP = 0 THEN
	CONTINUE;
      IF TEMP = LF THEN
	USERERR(0,1,"UNEXPECTED LF");
      WORDOUT(OUTCHAN,TEMP);
      IF TEMP = CR THEN
         BEGIN
            TEMP := WORDIN(INCHAN);
            IF EOF THEN
               USERERR(0,1,"UNEXPECTED EOF");
            IF TEMP NEQ LF THEN
               USERERR(0,1,"MISSING LF");
            WORDOUT(OUTCHAN,LF);
	    TEMP := WORDIN(INCHAN);
            IF EOF THEN
	        DONE;
            IF TEMP NEQ CR THEN
                GO TO LAB;
            TEMP := WORDIN(INCHAN);
            IF EOF THEN
		USERERR(0,1,"UNEXPECTED EOF");
            IF TEMP NEQ LF THEN
		USERERR(0,1,"MISSING LF");
         END;
    END;
    WRITE("SUCCESSFUL SINGLE SPACING");
END;