DISJ2 : term -> thm -> thm

SYNOPSIS
Introduces a left disjunct into the conclusion of a theorem.

DESCRIPTION
      A |- t2
   ---------------  DISJ2 `t1`
    A |- t1 \/ t2

FAILURE CONDITIONS
Fails if the term argument is not boolean.

EXAMPLE
  # DISJ2 `F` TRUTH;;
  val it : thm = |- F \/ T

SEE ALSO
DISJ1, DISJ1_TAC, DISJ2_TAC, DISJ_CASES.