small scale reflection library for Coq (theories)

 The name Ssreflect stands for "small scale reflection", a style of
 proof that evolved from the computer-checked proof of the Four Colour
 Theorem and which leverages the higher-order nature of Coq's
 underlying logic to provide effective automation for many small,
 clerical proof steps. This is often accomplished by restating
 ("reflecting") problems in a more concrete form, hence the name. For
 example, in the Ssreflect library, arithmetic comparison is not an
 abstract predicate, but a function computing a boolean.
 .
 The Ssreflect distribution comprises two parts:
 * A new tactic language, which promotes more structured, concise and
   robust proof scripts, and is in fact independent from the "reflection"
   proof style. It is implemented as a linkable extension to the Coq
   system.
 * A set of Coq libraries that provide core "reflection-oriented"
   theories for basic combinatorics (roughly: arithmetic, lists, and
   finite sets).
 .
 This package installs the full Ssreflect distribution.