Language = {an b an+3 | n >=0}
CFG
S-> a S a | a X a
X -> bC
C -> aaa
Valid strings
These strings must be accepted by our Context-free Grammar.
{ abaaaa, aabaaaaa, aaabaaaaaa,……… }
InValid strings
These strings must be rejected by our Context-free Grammar.
{ aba, aabaa, abba,……… }