type fixes and bindings + notes on subtyping

README.md

@@ -2,25 +2,24 @@
 
 experimental type system implementation
 
-## sappho grammar
+## getting and building
 
-```
-s, t ::= s | t              (disjunction, a.k.a. union)
-       | s & t              (conjunction, a.k.a. intersection)
-       | s => t             (implication)
-       | s -> t             (arrow, a.k.a. function)
-       | forall x . t       (forall, polymorphic)
-       | box t              (box, modular logic)
-       | a [t..]            (type operator application)
-       | x                  (variable)
-       | n                  (nominal)
-       | true               (true, a.k.a. top)
-       | false              (false, a.k.a. bottom)
-       | { m : t }          (member, a.k.a. atomic record)
-
-
-x ∈ var
-n ∈ nominal
-a ∈ opname
+```sh
+git clone ssh://git@gitta.log-e.se:222/lnsol/log-e-sappho.git
+cd ./log-e-sappho
+cmake . -B build
+cd build
+make
 ```
 
+## repository content
+
+This repository contains:
+
+* a library implementation of *sappho* called `spho`.
+* a simple language parser (and soon type checker), called `msph`, developed in
+  tandem with `spho`.
+* documentation of the sappho type system in `docs/`
+
+
+