From 45d473d44eea2236ed3f2df14d2db86fe5b5f348 Mon Sep 17 00:00:00 2001
From: Leonardo de Moura <leonardo@microsoft.com>
Date: Wed, 21 May 2014 11:31:34 -0700
Subject: [PATCH] feat(kernel): add mk_hott_environment function for creating
 HoTT compatible environments

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
---
 src/CMakeLists.txt             |  2 ++
 src/kernel/hott/CMakeLists.txt |  2 ++
 src/kernel/hott/hott.cpp       | 22 ++++++++++++++++++++++
 src/kernel/hott/hott.h         | 11 +++++++++++
 4 files changed, 37 insertions(+)
 create mode 100644 src/kernel/hott/CMakeLists.txt
 create mode 100644 src/kernel/hott/hott.cpp
 create mode 100644 src/kernel/hott/hott.h

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 576ca512c4..46c6c34319 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -217,6 +217,8 @@ add_subdirectory(kernel/inductive)
 set(LEAN_LIBS ${LEAN_LIBS} inductive)
 add_subdirectory(kernel/standard)
 set(LEAN_LIBS ${LEAN_LIBS} standard_kernel)
+add_subdirectory(kernel/hott)
+set(LEAN_LIBS ${LEAN_LIBS} hott_kernel)
 add_subdirectory(library)
 set(LEAN_LIBS ${LEAN_LIBS} library)
 # add_subdirectory(library/rewriter)
diff --git a/src/kernel/hott/CMakeLists.txt b/src/kernel/hott/CMakeLists.txt
new file mode 100644
index 0000000000..2e236d7ffa
--- /dev/null
+++ b/src/kernel/hott/CMakeLists.txt
@@ -0,0 +1,2 @@
+add_library(hott_kernel hott.cpp)
+target_link_libraries(hott_kernel ${LEAN_LIBS})
diff --git a/src/kernel/hott/hott.cpp b/src/kernel/hott/hott.cpp
new file mode 100644
index 0000000000..32922aa976
--- /dev/null
+++ b/src/kernel/hott/hott.cpp
@@ -0,0 +1,22 @@
+/*
+Copyright (c) 2014 Microsoft Corporation. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+
+Author: Leonardo de Moura
+*/
+#include "kernel/inductive/inductive.h"
+
+namespace lean {
+using inductive::inductive_normalizer_extension;
+
+/** \brief Create a HoTT (Homotopy Type Theory) compatible environment */
+environment mk_hott_environment(unsigned trust_lvl) {
+    return environment(trust_lvl,
+                       false /* Type.{0} is proof relevant */,
+                       true  /* Eta */,
+                       false /* Type.{0} is predicative */,
+                       list<name>(name("Id")) /* Exact equality types are proof irrelevant */,
+                       /* builtin support for inductive datatypes */
+                       std::unique_ptr<normalizer_extension>(new inductive_normalizer_extension()));
+}
+}
diff --git a/src/kernel/hott/hott.h b/src/kernel/hott/hott.h
new file mode 100644
index 0000000000..18c98be268
--- /dev/null
+++ b/src/kernel/hott/hott.h
@@ -0,0 +1,11 @@
+/*
+Copyright (c) 2014 Microsoft Corporation. All rights reserved.
+Released under Apache 2.0 license as described in the file LICENSE.
+
+Author: Leonardo de Moura
+*/
+#pragma once
+#include "kernel/environment.h"
+namespace lean {
+environment mk_hott_environment(unsigned trust_lvl = 0);
+}