Singular Manual: CoverMult

| #### D.15.31.4 CoverMult Procedure from library `tropicalEllipticCovers.lib` (see tropicalEllipticCovers_lib). Usage: CoverMult(G,aa,O,t[, l]); G graph, aa list, O list, t int, l list Assume: G is a Feynman graph, aa is a partition of the degree of the graph G, O is a given ordering of the vertices of G, l is a list of leaks of G and t is some integer between 0 and 3. Return: list. Theory: For a given ordering of the vertices of G, this function computes a list of multiplicity for each cover of G. Each entry in the list is a multiplicity of a cover of G. (For t=0, we get the results for simply ramified covers [BBM]. t=1, 2 we get results for graphs w/o vertex contributions respectively w/ vertex contributions as in [BGM1], and for t=3 we get the results for pearl chains as in [BGM2]) Example:
    LIB "tropicalEllipticCovers.lib";
    ring r=0, (x1,x2,x3,x4),dp;
    graph G=makeGraph(list(1,2,3,4),list(list(1,3),list(1,2),list(1,2),list(2,4),list(3,4),list(3,4)));
    CoverMult(G,list(0,2,1,0,0,1), list(x2,x4,x3,x1),0);

User manual for Singular version 4.4.1, 2025, generated by texi2html.