# Starting points

- Introduce yourself to logic concepts through
**pictures**.

This site has explanations of concepts at work in mathematical logic
and the Prooftoys system, with interactive pictures like these:

Move on to:

**The logic**of Prooftoys, and**logical inference**.*Proofs*about**logic**and**the real numbers**. Understand in detail or just browse.**Building your own proofs**with the online*proof builder*. This tool has some rough edges still, but don’t worry; it will only do correct inferences.

A more finished version of the proof builder
is targeted for solving simple equations, at the
companion **Mathtoys** site.