# Circom Authors - Constraint Generation (Highlights)  ## Highlights - All constraints must be quadratic of the form A*B + C = 0, where A, B and C are linear combinations of signals. ([View Highlight](https://read.readwise.io/read/01hs4eehzcv9jncpdnbzxer6xw)) ^693692767 - As mentioned before, assigning a value to a signal using `<--` and `-->` is considered dangerous and should, in general, be combined with adding constraints with `===`, which describe by means of constraints which the assigned values are. ([View Highlight](https://read.readwise.io/read/01hs4ehs51cbd7efzgc8ak8p61)) ^693692975 - Other arithmetic expressions beyond quadratic or using other arithmetic operators like division or power are not allowed as constraints. ([View Highlight](https://read.readwise.io/read/01hs4ejtb4f0ak60yf047x1twt)) ^693693062