Do not use the ipmon -a syntax if the ipmon daemon is still running. Normally, the daemon is automatically started during system boot. Issuing the ipmon -a command also opens another copy of ipmon. In such a case, both copies read the same log information, and only one gets a particular log message.
Substitution method is a method of solving a system of equations wherein one of the equations is solved for one variable in terms of the other variables.
1 Involution (mathematics), the broader concept: a function that is its own inverse (when applied twice, the starting value is obtained).  Inversion (discrete mathematics), any item that is out of order in a sequence.