# Difference between the two npda languages

#### zulfi100

Joined Jun 7, 2012
629
Hi,
I have to got two questions related to npda:

Q1. Construct an npda for L = {a_concate_n b_concate_2n | n ≥ 0} on Σ= {a, b, c}.
& the language in the following question:

Q2. Construct an npda for L = {w ∈ {a, b, c}* | na(w) = 2nb(w)}

What is the difference in the above two languages?

Zulfi.

#### WBahn

Joined Mar 31, 2012
24,974
Which, if either, of the languages is the string "aabc" in?

Which, if either, of the languages is the string "abb" in?

Which, if either, of the languages is the string "baa" in?

#### zulfi100

Joined Jun 7, 2012
629
Hi,
Which, if either, of the languages is the string "aabc" in? Second one: I was confusing with 'c'. Is the number of c's independent to 'a's and 'b's in the 2nd one?

Which, if either, of the languages is the string "abb" in? first one. Can we have a string with 'c' in the first one?

Which, if either, of the languages is the string "baa" in? : Second one: We can change the order in the second one.

Zulfi.