regular languages with concatenations...

Validate string given Context Free Grammar in Java...

Construct a CFG for...

constructing CFG...

Regular expression for formal languages...

formal languages: what does R-trivial mean?...

Formal regular expression for a language over a,b,c such that a is never adjacent to b...

What is the intersection of two languages with different alphabets?...

Deciding if a given Language is Regular/Context-Free/Non Context-Free...

Does this DFA have a solution?...

How to prove that L={w|#a(w)=#b(w)=#c(w)} is not context free using closure...

Formal grammar of XML...

How do I find the language from a regular expression?...

When you are proving a language is decidable, what are you effectively doing?...

Find a regular expression for strings containing the substring 01a and even number of 1's over t...

Understanding Σ* and Σ in formal languages...

Difference between L* and Σ*...

adding variables/types to a typing environment...

What kind of formal languages can modern regex engines parse?...

how can i see directly that a language is not regular...

How come we write programs in context-free languages? Shouldn't programs be in recursively enume...

Why is the complement of a regular language still a regular language?...

find Reg. Expr. over {0,1,2} so last symbol of string is the sum of the symbols so far on the string...

Find a non-deterministic CFL whose reverse is deterministic...

Production rules for a grammar...

Checking if a string consists of balanced parenthesis...

How to recognize English words via ANTLR?...

what is the length of a language that contains epsilon?...

Verifying that a grammar is strong LL(2)...

Is there an algorithm for determining if the set of all valid XML instances in respect with a specif...