How can R' Yochanan say there is only one other lav that depends on whether or not you do the aseh. What about the lav NOT TO LEAVE OVER THE KORBAN UNTIL MORNING...and then the ASEH to BURN IT?! that can be nullified...by eating it, or throwing it away...
Question, nj
The rule of Rebbi Yochanan is that these are the only Lavim that one becomes Patur from Malkus by performing the Aseh, and one is Chayav Malkus only if he makes the Aseh impossible to perform. In the case of Nosar that you mention, even if he does not burn the Korban, he does not get Malkus.
D. Zupnik
Why not?
Because leaving over Nosar is a Lav she'Ein Bo Ma'aseh, for which Malkus is not given (according to Rebbi Yochanan), as the Gemara explained on top of the page.
M. Kornfeld