### 2.6.21. System of constraints

Denotes that a constraint ${C}_{\mathrm{𝑎𝑙𝑠𝑜}}$ is a conjunction of constraints ${C}_{\mathrm{𝑒𝑛𝑡𝑟𝑦}}$ (see the keyword system of constraints).

EXAMPLE: As an example, the constraint ${C}_{\mathrm{𝑎𝑙𝑠𝑜}}=$ $\mathrm{𝚌𝚘𝚕𝚘𝚛𝚎𝚍}_\mathrm{𝚖𝚊𝚝𝚛𝚒𝚡}$ corresponds to a conjunction of constraints of the form ${C}_{\mathrm{𝑒𝑛𝑡𝑟𝑦}}=$ $\mathrm{𝚐𝚕𝚘𝚋𝚊𝚕}_\mathrm{𝚌𝚊𝚛𝚍𝚒𝚗𝚊𝚕𝚒𝚝𝚢}$: Given a matrix $ℳ$ of variables, the $\mathrm{𝚌𝚘𝚕𝚘𝚛𝚎𝚍}_\mathrm{𝚖𝚊𝚝𝚛𝚒𝚡}$ constraint forces a $\mathrm{𝚐𝚕𝚘𝚋𝚊𝚕}_\mathrm{𝚌𝚊𝚛𝚍𝚒𝚗𝚊𝚕𝚒𝚝𝚢}$ on each row and each column of $ℳ$.