const pk: Function;
secret sk: Function;
inversekeys (pk,sk);
const P1;

protocol nsl3th1(I,R)
{
	role I
	{
		fresh ni: Nonce;
		var nr: Nonce;

		send_1(I,R, {P1,I,ni}pk(R) );
		read_1b(R,I, {nr}pk(I) );
		read_2(R,I, {P1,ni,nr,R}pk(I) );
		send_3(I,R, {P1,nr}pk(R) );

		claim_i(I,Nisynch);
	}	
	
	role R
	{
		var ni: Nonce;
		fresh nr: Nonce;

		read_1(I,R, {P1,I,ni}pk(R) );
		send_1b(R,I, {nr}pk(I) );
		send_2(R,I, {P1,ni,nr,R}pk(I) );
		read_3(I,R, {P1,nr}pk(R) );

		claim_r(R,Nisynch);
	}
}