Pitching eligibility

[Rackster]

The actual situation was in our game today the starting pitcher went 3 innings,we brought next picher A in for the fourth inning and our intentions were to pitch pitcher B the last 2 innings.Well when we brought pitcher B in for the start of the fifth,the opposing manager questioned his eligibility and we realized he was only eligible for 1 inning.If we kept him in for the fifth inning we would have needed another pitcher for the sixth,so we decided to let pitcher A throw one more inning,which he did.Opposing coach then,as pitcher A warmed up for the 5th inning, questioned if pitcher B had used up his eligibility by also warming up.It was decided he hadn't and pitcher A pitched the 5th and B the sixth.I'm not so sure he didn't use up his eligibility tho. To take this a step furthur..if after we decided to let pitcher A go another inning and he started warming up,opposing coach says B has used up his eligibility by warming up,A is now an illegal pitcher.(Player removed as a pitcher can't pitch again that game)Could we go back to letting B pitch the 5th and get a different player to pitch the 6th or is B's eligibility done for the week? It seems I remember hearing about a rule years ago that stated something like "any pitcher who warms up from the playing field mound must pitch at least 1 pitch to a batter.",thus,effectively being charged with an inning pitched,but I can't find anything in the rule book confirming this except the above quoted regulation.