MHB Are the regular expressions the same?

[evinda]

Hi!I have also an other question.

Is the regular expression $\{\{a,b,c\}^{*} \cdot aba \cdot \{a,b,c\}^{*}\}\cap\{\{a,b,c\}^{*} \cdot cbc \cdot \{a,b,c\}^{*}\}$ equal to this one: $\{\{a,b,c\}^{*} \cdot aba \cdot \{a,b,c\}^{*} \cdot cbc \cdot \{a,b,c\}^{*}$ or is there a difference?

 

[Evgeny.Makarov]

$\{\{a,b,c\}^{*} \cdot aba \cdot \{a,b,c\}^{*}\}\cap\{\{a,b,c\}^{*} \cdot cbc \cdot \{a,b,c\}^{*}\}$ is not a regular expression because it contains $\cap$.

 

[evinda]

$\{\{a,b,c\}^{*} \cdot aba \cdot \{a,b,c\}^{*}\}\cap\{\{a,b,c\}^{*} \cdot cbc \cdot \{a,b,c\}^{*}\}$ is not a regular expression because it contains $\cap$.

I understand...Thank you very much!