Singular Manual: LRmult

| #### D.15.8.4 LRmult Procedure from library `lrcalc.lib` (see lrcalc_lib). Usage: LRmult(x, y); x, y lists of integers (partitions) LRmult(x, y [, s, r]); x, y lists of integers (partitions), s string equal to 'r', r integer LRmult(x, y [, s, m, k]); x, y lists of integers (partitions), s string equal to 'q' or 'f', m, k integers Return: list of lists Purpose: computes the partitions z for which the Littlewood-Richardson coefficient c^z_{x,y} is non-zero together with that coefficient; partitions up to length r Note: Example:
    LIB "lrcalc.lib";
    // Compute the partitions z for which the Littlewood-Richardson coefficient
    // c^z_{x,y} is non-zero together with that coefficient
    // for x= (2, 1), y=(2, 1)
    list x = 2, 1;
    list y = 2, 1;
    LRmult(x, y);
    // Now compute only the partitions with at most 2 entries
    LRmult(x, y, "r", 2);
    // Now compute the product in the quantum cohomology ring of the Grassmannian Gr(3,3+2).
    LRmult(x, y, "q", 3, 2);
    // Compute the same product with the output given in fusion ring notation
    LRmult(x, y, "f", 3, 2);

User manual for Singular version 4.3.2, 2023, generated by texi2html.