FUNCTION :  cuspquiv1 - determines whether two cusps ate GAMMA[1](N)-equivalent

CALLING SEQUENCE :  cuspequiv1()                                
                    cuspequiv1(a1,c1,a2,c2,N)                                

PARAMETERS :      a1,c1,a2,c2 - integers
                  N - positive integer

GLOBAL VARIABLES:   none               

SYNOPSIS :   Determines whether the cusps a1/c1 and a2/c2 are      
             Gamma[1](N)-equivalent.                               
   
EXAMPLES :   

> with(thetaids):

> cuspequiv1();
---------------------------------------------------------
cuspequiv1(a1,c1,a2,c2,N)                                
   Determines whether the cusps a1/c1 and a2/c2 are      
   Gamma[1](N)-equivalent.                               
---------------------------------------------------------

> cuspequiv1(1,0,1,420,420);
                                     true

> C420:=cuspmake1(420):
> nops(C420);
                                      960

> 
> for s in C420 do                                 
> if cuspequiv1(151,1601,op(s),420) then print(s);fi:od:
                                    [1, 79]


DISCUSSION :

We see that the cusps oo=1/0 and 1/420 are GAMMA[1](420)-equivalent.
There are 960 inequivalent cusps of GAMMA[1](420).
We found that the cusps 151/1601 and 1/79 are GAMMA[1](420)-equivalent.

SEE ALSO :  

cuspsetinequiv1,
 cuspmake1