late if syntax

Defining logical valiables

We can define a logical variable logvar as follows:

  
  \newif\iflogvar

By default, it is set to false. We can set it to true by:

  
  \logvartrue

and back to false by:

  
  \logvarfalse

The variable can be used in a conditional as follows:

  
  \iflogvar
  aaaa
  \else
  bbbb
  \fi