\DOC Cases_on
\TYPE {Cases_on : term -> tactic}
\SYNOPSIS
Performs case analysis on the type of a given term.
\KEYWORDS
tactic
\LIBRARY
SingleStep
\DESCRIBE
An application {Cases_on M} performs a case-split based on the type {ty}
of {M}, using the cases theorem for {ty} from the global {TypeBase}
database.
{Cases_on} can be used to specify variables that are buried
in the quantifier prefix. {Cases_on} can also be used to perform
case splits on non-variable terms. If {M} is a non-variable term that
does not occur bound in the goal, then the cases theorem is instantiated
with {M} and used to generate as many sub-goals as there are disjuncts
in the cases theorem.
\FAILURE
Fails if {ty} does not have a case theorem in the {TypeBase}.
\EXAMPLE
None yet.
\SEEALSO
bossLib.Cases, bossLib.Induct,
bossLib.Induct_on, Tactic.STRUCT_CASES_TAC.
\ENDDOC