b2 b2 b3 b2 b3 b4
a1, a1 + --, a1 + -- --, a1 + -- -- --, ...
a2 a2 + a3 a2 + a3 + a4
reduced to the forms
a1 a1a2 + b2 a1a2a3 + b2a3 + b2a1
--, ---------, --------------------,
1 a2 a2a3 + b3
a1a2a3a4 + b2a3a4 + b3a1a4 + b4a1a2 + b2b4
------------------------------------------, ...
a2a3a4 + a4b3 + a2b4
are called the successive convergents to the general continued fraction.
Their numerators are denoted by p1, p2, p3, p4...; their
denominators by q1, q2, q3, q4....