MHB Equivalence Between NFA and DFA: Q, Q` & $\Sigma$

  • Thread starter Thread starter mathmari
  • Start date Start date
  • Tags Tags
    Dfa Equivalence
Click For Summary
The discussion focuses on the equivalence between a Non-deterministic Finite Automaton (NFA) and a Deterministic Finite Automaton (DFA). It establishes that for states Q_I and Q_j in the DFA, the condition for Q_I transitioning to Q_j with input 'a' is that Q_j equals the union of states reachable from Q_I after processing 'a' and any number of ε transitions. Specifically, Q_j can be expressed as the set of states that can be reached from any state in Q_I through a sequence of transitions involving 'a' followed by ε transitions. This relationship is critical for understanding how NFAs and DFAs can be converted into one another. The discussion emphasizes the importance of ε transitions in determining state reachability in the context of automata theory.
mathmari
Gold Member
MHB
Messages
4,984
Reaction score
7
Heloo! :o

I am looking at the equivalence between a NFA and a DFA.

NFA: Q={q1,q2}
DFA: Q`=P(Q}

When $a\in \Sigma, Q_I, Q_j \in Q`$ which is sufficient and necessary condition so that $ Q_I \overset{a}{\rightarrow}Q_j$?
 
Last edited by a moderator:
Physics news on Phys.org
mathmari said:
When $a\in \Sigma, Q_I, Q_j \in Q`$ which is sufficient and necessary condition so that $ Q_I \overset{a}{\rightarrow}Q_j$?
This is described in the books we talked about. Namely, if $R\in Q'$, i.e., $R\subseteq Q$, let
\[
E(R)=\{q\in Q\mid q\text{ can be reached from }R\text{ by 0 or more }\varepsilon\text{ arrows}\}.
\]
Then $Q_i \overset{a}{\rightarrow}Q_j$ iff $$Q_j=\bigcup_{q\in Q_i}E(\delta(q,a))$$. In other words,
\[
Q_j=\{s\in Q\mid q\overset{a}{\to}r\overset{\varepsilon}{\to}\!\!^*s\text{ for some }q\in Q_i\}.
\]
Here $r\overset{\varepsilon}{\to}\!\!^*s$ means that $s$ can be reached from r by 0 or more $\varepsilon$ arrows.
 
Evgeny.Makarov said:
This is described in the books we talked about. Namely, if $R\in Q'$, i.e., $R\subseteq Q$, let
\[
E(R)=\{q\in Q\mid q\text{ can be reached from }R\text{ by 0 or more }\varepsilon\text{ arrows}\}.
\]
Then $Q_i \overset{a}{\rightarrow}Q_j$ iff $$Q_j=\bigcup_{q\in Q_i}E(\delta(q,a))$$. In other words,
\[
Q_j=\{s\in Q\mid q\overset{a}{\to}r\overset{\varepsilon}{\to}\!\!^*s\text{ for some }q\in Q_i\}.
\]
Here $r\overset{\varepsilon}{\to}\!\!^*s$ means that $s$ can be reached from r by 0 or more $\varepsilon$ arrows.

Ok... Thanks a lot! (Smile)
 
If there are an infinite number of natural numbers, and an infinite number of fractions in between any two natural numbers, and an infinite number of fractions in between any two of those fractions, and an infinite number of fractions in between any two of those fractions, and an infinite number of fractions in between any two of those fractions, and... then that must mean that there are not only infinite infinities, but an infinite number of those infinities. and an infinite number of those...

Similar threads

  • · Replies 6 ·
Replies
6
Views
4K
Replies
6
Views
3K
  • · Replies 15 ·
Replies
15
Views
3K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 11 ·
Replies
11
Views
2K
  • · Replies 18 ·
Replies
18
Views
2K