# Pastebin uJUqZ5mb
So, propose the following security definition.

"Every ppt Algo A that outputs a pair of pairs ((m, R, S), w) and ((m*, R*, S*), w*) has a negligible probability that all the following are satisfied:
 1) VERIFY(m, R, S) = 1 and
 2) VERIFY(m*, R*, S*) = 1 and
 3) w is a witness for signature S and
 4) w* is a witness for signature S* and
 5) one of the following mutually exclusive conditions is true:
        (i)  \texttt{LINK}((m, R, S), (m*, R^*, S*)) = 1 and w != w*, or
        (ii) \texttt{LINK}((m, R, S), (m*, R^*, S*)) = 0 and w = w*."