FUNCTION : qseries[quinprod] - Watson's quintuple product CALLING SEQUENCE : quinprod(a,b,q,T) PARAMETERS : a,b,q - names T - positive integer or one of the names prodid or seriesid SYNOPSIS : CASE 1. T is a positive integer T quinprod(a,b,q,T) returns the q-series expansion to order O(q ) of Watson's quintuple product where z and q are real or complex variables (or constants) and where z is nonzero and |q|<1. Here T is postive integer. The expansion is found using the quintuple product identity. CASE 2. T = prodid quinprod(a,b,q,prodid) returns the quintuple product identity in product form. CASE 3. T = seriesid quinprod(a,b,q,prodid) returns the quintuple product identity in series form. EXAMPLES : ------------------------------------------------------------------------- > quinprod(z,q,prodid); 2 2 (- z, q) (- q/z, q) (z q, q ) oo oo oo q 2 (----, q ) (q, q) = 2 oo oo z 2 q 3 3 3 3 3 (----, q ) (q z , q ) (q , q ) 3 oo oo oo z q 3 2 3 3 3 3 + z (----, q ) (q z , q ) (q , q ) 3 oo oo oo z --------------------------------------------------------------------------- > quinprod(z,q,seriesid); 2 2 (- z, q) (- q/z, q) (z q, q ) oo oo oo q 2 (----, q ) (q, q) = 2 oo oo infinity ----- \ (- 3 m) (3 m - 1) (1/2 m (3 m + 1)) ) ((- z) - (- z) ) q / ----- m = - infinity ---------------------------------------------------------------------------- > quinprod(z,q,3); / 12 1 \ 22 / 9 1 \ 12 / 6 1 \ 5 / 3 1 \ |z + ---| q + |- z - ----| q + |z + ----| q + |- z - ----| q + 1 + z | 11| | 8 | | 5 | | 2 | \ z / \ z / \ z / \ z / / 1 4\ 2 / 1 7\ 7 / 1 10\ 15 / 1 13\ 26 + |- ---- - z | q + |---- + z | q + |- ---- - z | q + |--- + z | q | 3 | | 6 | | 9 | | 12 | \ z / \ z / \ z / \z / ---------------------------------------------------------------------------- SEE ALSO :