Metacharacters

Question

"(4{5,6})\1"
why it is matched to 10 to 12 fours and not 5 to 6 fours?

Answer 1

(4{5,6}) matches 5 fours or 6 fours.
if the group value is 5 fours then \1 value is equally 5 fours = 10 fours.
if the group value is 6 fours then \1 value is equally 6 fours = 12 fours.