From a Baidu page about 拉丁矩 (Latin rectangles, a topic in combinatorial mathematics, and one of my research topics), we have the following sentence (listed as 定义1; I trim back some of the mathematics notation):
设A是一个m×s矩阵,若A的任一行是集{1,...,n}的一个s-排列,任一列是集{1,...,n}的一个m-排列,则称A是一个m×s拉丁矩。
I translate this to something like:
If A is an m×s matrix, such that every row is an s-permutation of {1,...,n} and every column is an m-permutation of {1,...,n}, then A is a Latin rectangle.
I'm confused about the grammar here, and in particular, the use of (what seems to be) the following:
设A是[a mathematical object], 若A的[conditions], 则称A是[a special type of that mathematical object].
I'm seeking a better overall idea of how this structure works, e.g., how frequently this is used, other examples, and what 设, 若, 则 and 称 are doing in the sentence.
Question: How does 设A是..., 若A的..., 则称A是... work for mathematical definitions?