100 PROGRAM "Leapyear.bas"
110 FOR I=1990 TO 2020
120   IF LEAPY(I) THEN
130     PRINT I;"is a leap year."
140   ELSE
150     PRINT I;"is not a leap year."
160   END IF
170 NEXT
180 DEF LEAPY(Y)=MOD(Y,4)=0 AND MOD(Y,100) OR MOD(Y,400)=0