5 DIM T(8)
10 PRINT "INPUT 'LOWER LIMIT, UPPER LIMIT' (TO END PROGRAM INPUT" 
11 PRINT "EQUAL LIMITS)"  
20 INPUT X1,X2  
30 IF X2=X1 THEN 999  
40 L=X2-X1  
50 Y1=FNC(X1) 
60 Y=FNC(X2)  
70 T(1)=(Y1+Y)/2  
80 N=1  
90 FOR H=1 TO 7
100 U=0 
110 M=L/(2*N) 
120 FOR J=1 TO 2*N-1 STEP 2 
130 Y=FNC(X1+J*M) 
140 U=U+Y 
150 NEXT J  
160 T(H+1)=(U/N+T(H))/2
170 F=1 
180 FOR J=H TO 1 STEP -1  
190 F=F*4
200 T(J)=T(J+1)+(T(J+1)-T(J))/(F-1) 
210 NEXT J  
220 N=2*N
230 I2=T(1)*L 
240 IF H=1 THEN 260
250 IF ABS(I1-I2)<=1E-4*ABS(I2) THEN 400 
260 I1=I2
270 NEXT H  
280 PRINT "UNABLE TO COMPUTE INTEGRAL TO 4 SIGNIFICANT DIGITS." 
290 PRINT "CLOSEST APPROXIMATION IS:";I2 
295 PRINT 
300 PRINT "INPUT 'LOWER LIMIT, UPPER LIMIT'"  
310 GOTO 20 
400 PRINT "INTEGRAL= ";I2
410 GOTO 295 
999 END 

