### 2.6.16. Related to a common problem

Denotes that a constraint ${C}_{\mathrm{𝑒𝑛𝑡𝑟𝑦}}$ and a constraint ${C}_{\mathrm{𝑎𝑙𝑠𝑜}}$ are related to a same problem (i.e., they can both be used for modelling that problem).

EXAMPLE: As an example, the constraints ${C}_{\mathrm{𝑒𝑛𝑡𝑟𝑦}}=$ $\mathrm{𝚌𝚘𝚕𝚘𝚛𝚎𝚍}_\mathrm{𝚖𝚊𝚝𝚛𝚒𝚡}$ and ${C}_{\mathrm{𝑎𝑙𝑠𝑜}}=$ $\mathrm{𝚜𝚊𝚖𝚎}$ can both be used for modelling the matrix reconstruction problem.