Talk:Matrix grammar

This article uses a function W but does not define it. Is W(V) = V^*? --137.158.142.58 (talk) 14:23, 3 March 2011 (UTC)

Contradictory content

This article contains contradictory information. In section Properties is says There exists some languages in MAT^\lambda which can not be produced by a context-sensitive grammar, but then in section open problems is says that it's it is neither known whether MAT^\lambda contains languages which are not context-sensitive.

I would guess that either the second information is outdated or its a typo meaning MAT (without \lambda), but since there are both possibilities I didn't edit anything in the article. — Preceding unsigned comment added by 46.183.96.139 (talk) 19:41, 31 August 2015 (UTC)

I checked Păun's book "Membrane Computing: An Introduction", and on page 32 it says $CS-MAT^{\lambda }\neq \emptyset$. Somewhat further down the text the book says that it is still an open problem whether $MAT^{\lambda }-CS$ is empty. I fixed the last but one property in the present article accordingly. (The corresponding pages of Păun's should normally be viewable via Gооgle Books.) Scolobb (talk) 19:44, 1 October 2015 (UTC)