BEGIN
owninteger fail=0
INTEGER I
INTEGERFN FACT(INTEGER N)
      IF N<=1 THENRESULT=1
      RESULT=N*FACT(N-1)
END
ROUTINE COMPARE(INTEGER I,J)
      UNLESS I=J START
         PRINTSTRING("ERROR")
         WRITE(I,5); WRITE(J,5)
         Fail=1; NEWLINE
      FINISH
END
      COMPARE(FACT(I),I*FACT(I-1)) FOR I=2,1,10
      if fail=0 then printstring("TEST OK")
ENDOFPROGRAM