diff options
| author | Théo Zimmermann | 2020-06-08 13:35:29 +0200 |
|---|---|---|
| committer | Théo Zimmermann | 2020-06-09 13:32:12 +0200 |
| commit | 7fa123e4380b0de201088ebbe6720a0a60a56f21 (patch) | |
| tree | 72ade6debf664d1e5b9144b15854b930a1c20abe /doc | |
| parent | fcbae04dbe2e0777e2901cd4dff3bb5d482e3bc2 (diff) | |
Minor improvements to the section on sorts.
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/sphinx/addendum/universe-polymorphism.rst | 3 | ||||
| -rw-r--r-- | doc/sphinx/language/core/sorts.rst | 24 |
2 files changed, 15 insertions, 12 deletions
diff --git a/doc/sphinx/addendum/universe-polymorphism.rst b/doc/sphinx/addendum/universe-polymorphism.rst index 12fd038fb6..b0ef792bd1 100644 --- a/doc/sphinx/addendum/universe-polymorphism.rst +++ b/doc/sphinx/addendum/universe-polymorphism.rst @@ -361,6 +361,7 @@ it is an atomic universe (i.e. not an algebraic max() universe). to the sort :g:`Set` and only collapses floating universes between themselves. +.. _explicit-universes: Explicit Universes ------------------- @@ -387,7 +388,7 @@ to universes and explicitly instantiate polymorphic definitions. Polymorphic Universe @ident In the monorphic case, this command declares a new global universe - named :g:`ident`, which can be referred to using its qualified name + named :token:`ident`, which can be referred to using its qualified name as well. Global universe names live in a separate namespace. The command supports the :attr:`universes(polymorphic)` attribute (or the ``Polymorphic`` prefix) only in sections, meaning the universe diff --git a/doc/sphinx/language/core/sorts.rst b/doc/sphinx/language/core/sorts.rst index 03581b95dd..3517d70005 100644 --- a/doc/sphinx/language/core/sorts.rst +++ b/doc/sphinx/language/core/sorts.rst @@ -30,14 +30,16 @@ and :math:`\Set`. The sort :math:`\Prop` intends to be the type of logical propositions. If :math:`M` is a logical proposition then it denotes the class of terms representing -proofs of :math:`M`. An object :math:`m` belonging to :math:`M` witnesses the fact that :math:`M` is -provable. An object of type :math:`\Prop` is called a proposition. +proofs of :math:`M`. An object :math:`m` belonging to :math:`M` +:term:`witnesses <witness>` the fact that :math:`M` is +provable. An object of type :math:`\Prop` is called a :gdef:`proposition`. We denote propositions by :n:`@form`. This constitutes a semantic subclass of the syntactic class :n:`@term`. The sort :math:`\SProp` is like :math:`\Prop` but the propositions in :math:`\SProp` are known to have irrelevant proofs (all proofs are -equal). Objects of type :math:`\SProp` are called strict propositions. +equal). Objects of type :math:`\SProp` are called +:gdef:`strict propositions <strict proposition>`. See :ref:`sprop` for information about using :math:`\SProp`, and :cite:`Gilbert:POPL2019` for meta theoretical considerations. @@ -66,12 +68,12 @@ Formally, we call :math:`\Sort` the set of sorts which is defined by: \Sort \equiv \{\SProp,\Prop,\Set,\Type(i)\;|\; i~∈ ℕ\} -Their properties, such as: :math:`\Prop:\Type(1)`, :math:`\Set:\Type(1)`, and -:math:`\Type(i):\Type(i+1)`, are defined in Section :ref:`subtyping-rules`. +Their properties, such as :math:`\Prop:\Type(1)`, :math:`\Set:\Type(1)`, and +:math:`\Type(i):\Type(i+1)`, are described in :ref:`subtyping-rules`. The user does not have to mention explicitly the index :math:`i` when -referring to the universe :math:`\Type(i)`. One only writes :math:`\Type`. The system -itself generates for each instance of :math:`\Type` a new index for the +referring to the universe :math:`\Type(i)`. One only writes `Type`. The system +itself generates for each instance of `Type` a new index for the universe and checks that the constraints between these indexes can be solved. From the user point of view we consequently have :math:`\Type:\Type`. We shall make precise in the typing rules the constraints between the @@ -81,8 +83,8 @@ indices. .. _Implementation-issues: **Implementation issues** In practice, the Type hierarchy is -implemented using *algebraic -universes*. An algebraic universe :math:`u` is either a variable (a qualified +implemented using algebraic universes. +An :gdef:`algebraic universe` :math:`u` is either a variable (a qualified identifier with a number) or a successor of an algebraic universe (an expression :math:`u+1`), or an upper bound of algebraic universes (an expression :math:`\max(u_1 ,...,u_n )`), or the base universe (the expression @@ -94,6 +96,6 @@ constraints between the universe variables is maintained globally. To ensure the existence of a mapping of the universes to the positive integers, the graph of constraints must remain acyclic. Typing expressions that violate the acyclicity of the graph of constraints -results in a Universe inconsistency error. +results in a :exn:`Universe inconsistency` error. -.. seealso:: :ref:`printing-universes`. +.. seealso:: :ref:`printing-universes`, :ref:`explicit-universes`. |
