FUNCTION : CHECKRAMIDF - checks whether an expression in terms of G, H is a likely etaproduct CALLING SEQUENCE : CHECKRAMIDF(SYMF,ACC,T) PARAMETERS : SYMF - symbolic expression in _G, _H ACC - integer T - integer GLOBAL VARIABLES: S,S2,_JFUNC,LDQ,RID,SYMID, qthreshold,proveit,ebasethreshold,ebtprob, EBL,PL,CHECKSYMF SYNOPSIS : The functions G,H,GM,HM must be defined before CHECKRAMIDF can be used. CHECKRAMIDF(SYMF,ACC,T) determines whether SYMF is a likely etaproduct. Here ACC is max abs value of exponents in the formal product. T is the largest power of q tested. If suspects an etaproduct a list of exponents is returned, otherwise NULL is returned. EXAMPLES : > with(qseries): > with(thetaids): > with(ramarobinsids): > G:=j->1/GetaL([1],10,j):H:=j->1/GetaL([3],10,j): > GM:=j->1/MGetaL([1],10,j): HM:=j->1/MGetaL([3],10,j): > SYMID1:=_G(6)*_H(1)-_G(1)*_H(6); _G(6) _H(1) - _G(1) _H(6) > CHECKRAMIDF(SYMID1,10,100); [0, 0, 0, 1, 1, -1, 0, 1, 0, -1, 0, 1, 0, 0, 0, 1, 0, -1, 0, 0, 0, 0, 0, 1, 1, 0, 0, 1, 0, 0, 0, 1, 0, 0, 1, 1, 0, 0, 0, 0, 0, -1, 0, 1, 0, 0, 0, 1, 0, -1, 0, 1, 0, -1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, -1, 0, 1, 0, -1, 0, 1, 0, 0, 0, 1, 0, -1, 0] > series(jac2series(_JFUNC,200)*q^(25/12),q,200): > etamake(%,q,60); (25/12) 3 q eta(30 tau) eta(12 tau) eta(5 tau) eta(4 tau) ------------------------------------------------------- 2 2 eta(60 tau) eta(15 tau) eta(10 tau) eta(6 tau) EXAMPLES : It seems that when G(1)=1/eta[10,1](tau), H(1)=1/eta[10,3](tau) G(6)H(1) - G(1)H(6) is an eta-product. SEE ALSO :