[JackFr]

> Like, it gets used a lot in SQL

Except it explicitly is not strictly Boolean in SQL because of nulls.

X = Y can take the value true, false or null if either or both X and Y are null.

[mcdonje]

I thought about mentioning nulls, but it's a complicated subject. Not all columns are nullable. Null handling rules differ. It's not always ISO/ANSI.