Table 3:

RE operators used in this study

Operator	Symbol	Description	Arity
Concatenation	Ø (invisible)	Concatenate two elements	2
Alternative choice (or)	|	Choice between two elements	2
Quantifier 1,n	+	Define a group present once or n time	1
Curly braces	{ }	Define the number of times the element is repeated	1
Bracket	[ ]	Define a list of choice between elements in the bracket	1
Excluding bracket	[^]	Define a list of choice between elements that are not in the bracket	1
Parenthesis	( )	Define a group	1