diff --git a/samples/sample.aritm.txt b/samples/sample.aritm.txt
index 189e263..d51eeca 100644
--- a/samples/sample.aritm.txt
+++ b/samples/sample.aritm.txt
@@ -10,11 +10,13 @@
 1100 REM 876543210, 8:TYPE, 7-5:OP1, 4-3:OP2, 2:RES'D, 1-0:#TODO.
 1110 REM PROGRAM:
 1112 GOTO 1115
-1113 MD=INT((X/Y-INT(X/Y))*Y+.5):RETURN
-1114 DIV=INT(X/Y+.5):RETURN
-1115 LET R=RND(-1)
+1113 STOP
+1114 STOP
+1115 LET R=RND(-PEEK(78)-PEEK(79)*256)
 1116 TEXT:PR#3:PRINT CHR$(17);CHR$(12);
 1117 DIM A(590)
+1118 DEF FN MD(Y)=INT((X/Y-INT(X/Y))*Y+.5)
+1119 DEF FN DIV(Y)=INT(X/Y+.5)
 1120 REM LBL C
 1130 GOSUB 3410:REM CLS
 1140 LET A=0
@@ -28,8 +30,8 @@
 1220 LET U=1
 1230 REM DIM A(N)
 1240 REM LBL ADD1
-1250 X=M:Y=10:GOSUB 1114:X=DIV:GOSUB 1113
-1255 IF 0=MD GOTO 1320:REM ADD2
+1250 X=M:Y=10:X=FN DIV(Y)
+1255 IF 0=FN MD(Y) GOTO 1320:REM ADD2
 1260 FOR I=0 TO 9
 1270 FOR J=0 TO 9
 1280 LET A(U)=100000000+I*100000+J*1000+1
@@ -37,8 +39,8 @@
 1300 NEXT J
 1310 NEXT I
 1320 REM LBL ADD2
-1330 X=M:Y=100:GOSUB 1114:X=DIV:Y=10:GOSUB 1113
-1335 IF 0=MD GOTO 1410:REM SUB1
+1330 X=M:X=FN DIV(100)
+1335 IF 0=FN MD(10) GOTO 1410:REM SUB1
 1340 FOR I=0 TO 9
 1350 FOR J=0 TO 9
 1360 LET T=10*(INT(8*RND(1))+1)
@@ -47,8 +49,8 @@
 1390 NEXT J
 1400 NEXT I
 1410 REM LBL SUB1
-1420 X=M:Y=1000:GOSUB 1114:X=DIV:Y=10:GOSUB 1113
-1425 IF 0=MD GOTO 1490:REM SUB2
+1420 X=M:X=FN DIV(1000)
+1425 IF 0=FN MD(10) GOTO 1490:REM SUB2
 1430 FOR I=0 TO 9
 1440 FOR J=I TO 9+I
 1450 LET A(U)=300000000+J*100000+I*1000+1
@@ -56,8 +58,8 @@
 1470 NEXT J
 1480 NEXT I
 1490 REM LBL SUB2
-1500 X=M:Y=10000:GOSUB 1114:X=DIV:Y=10:GOSUB 1113
-1505 IF 0=MD GOTO 1580:REM MUL
+1500 X=M:X=FN DIV(10000)
+1505 IF 0=FN MD(10) GOTO 1580:REM MUL
 1510 FOR I=0 TO 9
 1520 FOR J=I TO 9+I
 1530 LET T=10*(INT(9*RND(1))+1)
@@ -66,8 +68,8 @@
 1560 NEXT J
 1570 NEXT I
 1580 REM LBL MUL
-1590 X=M:Y=100000:GOSUB 1114:X=DIV:Y=10:GOSUB 1113
-1595 IF 0=MD GOTO 1660:REM DIV
+1590 X=M:X=FN DIV(100000)
+1595 IF 0=FN MD(10) GOTO 1660:REM DIV
 1600 FOR I=0 TO 9
 1610 FOR J=0 TO 9
 1620 LET A(U)=500000000+I*100000+J*1000+1
@@ -75,8 +77,8 @@
 1640 NEXT J
 1650 NEXT I
 1660 REM LBL DIV
-1670 X=M:Y=1000000:GOSUB 1114:X=DIV:Y=10:GOSUB 1113
-1675 IF 0=MD GOTO 1750:REM ENDIF
+1670 X=M:X=FN DIV(1000000)
+1675 IF 0=FN MD(10) GOTO 1750:REM ENDIF
 1680 FOR I=0 TO 9
 1690 FOR J=1 TO 9
 1700 LET T=I*J+INT(J*RND(1))
@@ -101,15 +103,15 @@
 1890 PRINT MID$(STR$(L),1);
 1895 PRINT " PROBLEMS LEFT. -1 ESC"
 1900 LET TF=A(K)
-1910 X=TF:Y=100000000:GOSUB 1114
-1915 LET C=DIV
+1910 X=TF
+1915 LET C=FN DIV(100000000)
 1920 IF 6=C THEN PRINT "INTEGER PART OF ";
-1930 X=TF:Y=100000:GOSUB 1114:X=DIV:Y=1000:GOSUB 1113
-1935 LET I=MD
+1930 X=TF:X=FN DIV(100000)
+1935 LET I=FN MD(1000)
 1940 PRINT MID$(STR$(I),1);
 1950 GOSUB 3280:REM SIGN
-1960 X=TF:Y=1000:GOSUB 1114:X=DIV:Y=100:GOSUB 1113
-1965 LET J=MD
+1960 X=TF:X=FN DIV(1000)
+1965 LET J=FN MD(100)
 1970 PRINT MID$(STR$(J),1);
 1980 PRINT " = ";:INPUT "";A$:A=VAL(A$)
 1985 PRINT
@@ -121,8 +123,8 @@
 2040 REM LBL ENDIF
 2050 IF ABS(R-A)>1E-6 GOTO 2140:REM WRONG
 2060 PRINT "RIGHT! ";
-2070 X=TF:Y=100:GOSUB 1113
-2075 IF 0>=MD GOTO 2100:REM ENDIF
+2070 X=TF
+2075 IF 0>=FN MD(100) GOTO 2100:REM ENDIF
 2080 LET L=L-1
 2090 LET A(K)=TF-1
 2100 REM LBL ENDIF
@@ -137,8 +139,8 @@
 2182 PRINT " IS ";
 2184 PRINT STR$(R);
 2186 PRINT "."
-2190 X=TF:Y=100:GOSUB 1113
-2195 IF 99<=MD GOTO 2220:REM ENDIF
+2190 X=TF
+2195 IF 99<=FN MD(100) GOTO 2220:REM ENDIF
 2200 LET L=L+1
 2210 LET A(K)=TF+1
 2220 REM LBL ENDIF
@@ -152,8 +154,8 @@
 2290 LET N=1
 2300 FOR K=1 TO U
 2310 LET TF=A(K)
-2320 X=TF:Y=100:GOSUB 1113
-2325 IF 0=MD GOTO 2350:REM ENDIF
+2320 X=TF
+2325 IF 0=FN MD(100) GOTO 2350:REM ENDIF
 2330 LET A(N)=TF
 2340 LET N=N+1
 2350 REM ENDIF
@@ -186,11 +188,11 @@
 2610 GOTO 2780:REM INPUT
 2640 REM SUB
 2650 LET A=A+1
-2660 X=TF:Y=10:GOSUB 1114
-2665 LET TF=DIV
+2660 X=TF
+2665 LET TF=FN DIV(10)
 2670 PRINT MID$(STR$(A),1);
-2680 X=TF:Y=10:GOSUB 1113
-2685 IF 0=MD GOTO 2720:REM ELSE
+2680 X=TF
+2685 IF 0=FN MD(10) GOTO 2720:REM ELSE
 2690 PRINT "*";
 2700 LET N=N+100-10*(6=A)
 2710 GOTO 2740:REM ENDIF
@@ -204,9 +206,9 @@
 2810 IF 0=A GOTO 1180:REM S
 2820 IF -1=A OR ".1"=A$ OR ",1"=A$ OR "01"=A$ GOTO 1120:REM C
 2830 GOSUB 3350:REM POW10
-2840 X=M:Y=R:GOSUB 1114:REM IDIV
-2842 X=DIV:Y=10:GOSUB 1113:REM MOD
-2845 IF 0=MD GOTO 2870:REM ELSE
+2840 X=M
+2842 X=FN DIV(R)
+2845 IF 0=FN MD(10) GOTO 2870:REM ELSE
 2850 LET M=M-R
 2860 GOTO 2890:REM ENDIF
 2870 REM LBL ELSE