FUNCTION AGM (a, g)
    DO
       LET ta = (a + g) / 2
       LET g = SQR(a * g)
       LET x = a
       LET a = ta
       LET ta = x
    LOOP UNTIL a = ta

    LET AGM = a
END FUNCTION

PRINT AGM(1, 1 / SQR(2))
END