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The Language MOREA ....

Posted by ian.coetzer 
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The Language MOREA ....
April 07, 2009 06:57PM
Hi, the textbook defines the language MOREA as follows:

= (all strings of a's and b's in which the total number of a's is greater than the total number of b's)
= (a aa aab aba baa aaab aaba ...}

Now, my question.

What about null strings??? will it be accepted by this language? I would guess yes because if the string contains no b's then the total numbers of a's need not be one, ...

Am I correct in my assumption or do you think that the smallest string accepted by this language is of length 1 and is "a" ?
avatar Re: The Language MOREA ....
April 07, 2009 08:43PM
I would say no. If the number of a's is m and the number of b's n then according to their definition m>n. So if n=0 then m must be at least 1.
Re: The Language MOREA ....
April 07, 2009 08:47PM
Alright, thanks
I understand that reasoning so I will also settle with that explanation,

In other words the number of a's must be greater than the number of b's,
therefore the minimum length must be (1) thus the word "a"

Where b = null, a = a, thus nulla = "a" or anull = "a"

Where the total length of the string = 2 the word must be "aa" since "ab" or "ba" contains an even number of a's and b's,
but for total word length of 3 we may have:


avatar Re: The Language MOREA ....
April 07, 2009 08:47PM
Ian, don't agree with you.
If you are referring to Q 5, p 454, then it states that "all strings with more a's than b's.
A /\ (null) string would not qualify because you would not have more a's than b's, you would have equal e.g. null.

Referring to first message.
Re: The Language MOREA ....
April 07, 2009 08:51PM
Thanks again,

Yip I'm going with that theory, therefore the following would ALL be valid strings in the language of MOREA:


edited this post ***removed the null string in this list !!! ***
avatar Re: The Language MOREA ....
April 07, 2009 09:34PM
Yes. Those strings are valid.
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