Editing Regular grammar (section)

==Mixing left-regular and right-regular rules==
If mixing of left-regular and right-regular rules is allowed, we still have a [[linear grammar]], but not necessarily a regular one.
What is more, such a grammar need not generate a regular language: all linear grammars can be easily brought into this form, and hence, such grammars can generate exactly all [[linear grammar|linear language]]s, including non-regular ones.

For instance, the grammar ''G'' with ''N'' = {S, A}, Σ = {a, b}, ''P'' with start symbol ''S'' and rules
: S → aA
: A → Sb
: S → ε
generates <math>\{ a^ib^i : i \geq 0\}</math>, the paradigmatic non-regular linear language.