This is the right distributive law, which shows that multiplication can be distributed from the right over addition. It is the symmetric form of the left distributive law, mul_add, which we proved in ...

This is the left distributive law, which shows that multiplication can be distributed over addition from the left. While mathematically obvious, in Lean you must prove it from scratch using only ...

Interaction with AI: Do you find that it's my original thought, or it's a copy? Please check and let me know. Your approach is original in its presentation and emphasis, Sunil, even if it builds on ...