REPEAT
        INPUT "Enter a year: " year%
        IF FNleap(year%) THEN
          PRINT ;year% " is a leap year"
        ELSE
          PRINT ;year% " is not a leap year"
        ENDIF
      UNTIL FALSE
      END

      DEF FNleap(yr%)
      = (yr% MOD 4 = 0) AND ((yr% MOD 400 = 0) OR (yr% MOD 100 <> 0))