10 LET A=1
 20 LET G=1/SQR 2
 30 GOSUB 100
 40 PRINT AGM
 50 STOP
100 LET A0=A
110 LET A=(A+G)/2
120 LET G=SQR (A0*G)
130 IF ABS(A-G)>.00000001 THEN GOTO 100
140 LET AGM=A
150 RETURN