if length of a = 0 that means b is not present in a so we return false
if len ( a ) == 0 : NEW_LINE INDENT return False NEW_LINE DEDENT if ( a [ 0 ] == b [ 0 ] ) : NEW_LINE INDENT return checkSequence ( a [ 1 : ] , b [ 1 : ] ) NEW_LINE DEDENT else : NEW_LINE INDENT return checkSequence ( a [ 1 : ] , b ) NEW_LINE DEDENT