h
direction the indicated axiom is being applied. 

-------------------------
 Axiom I1
-------------------------

   o   o         o
    \ /          |
     @     =     @

  ( ) ( )  =    ( )

-------------------------
 Axiom I2
-------------------------

     o
     |
     o
     |
     @     =     @

   (( ))   =

-------------------------
 Axiom J1
-------------------------

    xo           o
     |           |
    x@     =     @

   x(x)    =    ( )

-------------------------
 Axiom J2
---------------