Deduction eliminating a conjunct. (Contributed by NM, 14-May-1993.) A
translation of natural deduction rule /\ ER ( /\ elimination
right), see [natded]. (Proof shortened by Wolf Lammen, 3-Oct-2013.)
Deduction eliminating a conjunct. (Contributed by NM, 14-May-1993.) A
translation of natural deduction rule /\ ER ( /\ elimination
right), see [natded]. (Proof shortened by Wolf Lammen, 3-Oct-2013.)