User blog comment:LittlePeng9/Addition is commutative/@comment-24509095-20141002045140/@comment-2033667-20141002050826


 * \(A_n\) is nth axiom
 * \(R_=,S_=,T_=\) are reflexivity, symmetry, and transitivity of equality
 * \(\forall_E\) is universal elimination (substituting a concrete variable into \(\forall\))
 * \(\forall_I\) is universal introduction (slapping a universal quantifier on a statement, since no statement should have a free variable)
 * \(\wedge_I\) is conjunction introduction (combining two statements with a boolean AND)
 * \(MP\) is the classic modus ponens deduction (if p then q; p; therefore q)