FUNCTION :  qseries[findhommodp] - finds a set of potential homogeneous
                                   relations modp among a list of q-series.

CALLING SEQUENCE :  findhommodp(L,p,q,n,topshift)
    
PARAMETERS :   L   - list of q-series
               p   - prime
               q   - variable           
               n   - positive integer
               topshift - integer greater than -20      

GLOBAL VARIABLE : X

SYNOPSIS :   

 findhommodp is a modp version of findhom.     
   
 findhommodp(L,p,q,n,topshift) returns a set of potential homogenous relations
 mod p of order n among the q-series in the list L.
 The value of topshift is usually taken to be zero. Howeverm if
 it appears that spurious relations are being generated then a higher
 value of topshift should be taken.

 This program converts the list of q-series into a list of polynomials
 of a certain degree and then converts these into a matrix. The entries
 in a given row correspond to coefficients of the corrresponding the
 polynomial. The set of relations is then found by computing
 the kernel mod p of the transpose of this matrix.

NOTE: There is a global variable X that is reassigned each time the
function is called. This variable is used to display the relations.

CHANGES :
  1.3: o changed taylor to series to handle negative powers of q

EXAMPLES :   

SEE  ALSO :  findhom, findhomcombomodp