We compute the primary decomposition of certain ideals generated by subsets
of minors in a generic matrix or in a generic symmetric matrix, or subsets of
Pfaffians in a generic skew-symmetric matrix. Specifically, the ideals we
consider are generated by minors that have at least some given number of rows
and columns in certain submatrices.Comment: 10 pages. v2: minor corrections. v3: minor changes, final version to
appear in Comm. Al
