diff --git a/.github/workflows/cd.yml b/.github/workflows/cd.yml
index 73c2aff0..61586ffd 100644
--- a/.github/workflows/cd.yml
+++ b/.github/workflows/cd.yml
@@ -1,4 +1,4 @@
-# cspell:ignore noreply prereleased pypa reqs
+# cspell:ignore noreply prereleased
 
 name: CD
 
@@ -13,9 +13,6 @@ jobs:
     name: Push to stable branch
     if: startsWith(github.ref, 'refs/tags')
     runs-on: ubuntu-20.04
-    needs:
-      - documentation
-      - style
     steps:
       - uses: actions/checkout@master
       - name: Push to stable branch
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index c85c9cd1..ded01e02 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -7,16 +7,10 @@ on:
     branches: [master]
   pull_request:
     branches: [master]
-    types:
-      - opened
-      - synchronize
-      - reopened
-      - ready_for_review
 
 jobs:
   documentation:
     name: Build documentation and run notebooks
-    if: github.event.pull_request.draft == false
     runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v2
@@ -36,7 +30,6 @@ jobs:
 
   style:
     name: Style checks
-    if: github.event.pull_request.draft == false
     runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v2
diff --git a/.github/workflows/linkcheck.yml b/.github/workflows/linkcheck.yml
index 6022f494..780449bd 100644
--- a/.github/workflows/linkcheck.yml
+++ b/.github/workflows/linkcheck.yml
@@ -7,16 +7,11 @@ on:
     branches: [master]
   pull_request:
     branches: [master]
-    types:
-      - opened
-      - synchronize
-      - reopened
-      - ready_for_review
+  workflow_dispatch:
 
 jobs:
   check_links:
     name: Check external links
-    if: github.event.pull_request.draft == false
     runs-on: ubuntu-20.04
     steps:
       - uses: actions/checkout@v2
diff --git a/.github/workflows/release-drafter.yml b/.github/workflows/release-drafter.yml
index a3373592..e822364d 100644
--- a/.github/workflows/release-drafter.yml
+++ b/.github/workflows/release-drafter.yml
@@ -4,6 +4,7 @@ on:
   push:
     branches:
       - master
+  workflow_dispatch:
 
 jobs:
   update_release_draft:
diff --git a/.github/workflows/requirements-cron.yml b/.github/workflows/requirements-cron.yml
index 1f6b89e4..b4a7aefe 100644
--- a/.github/workflows/requirements-cron.yml
+++ b/.github/workflows/requirements-cron.yml
@@ -5,6 +5,7 @@ name: Requirements (scheduled)
 on:
   schedule:
     - cron: "0 2 * * 1"
+  workflow_dispatch:
 
 jobs:
   upgrade:
diff --git a/.github/workflows/requirements-pr.yml b/.github/workflows/requirements-pr.yml
index 4d2acc23..1b027b50 100644
--- a/.github/workflows/requirements-pr.yml
+++ b/.github/workflows/requirements-pr.yml
@@ -5,16 +5,10 @@ name: Requirements (PR)
 on:
   pull_request:
     branches: [master]
-    types:
-      - opened
-      - synchronize
-      - reopened
-      - ready_for_review
 
 jobs:
   upgrade:
     name: Upgrade requirement files
-    if: github.event.pull_request.draft == false
     runs-on: ubuntu-20.04
     strategy:
       matrix:
@@ -62,7 +56,6 @@ jobs:
 
   push:
     name: Push changes
-    if: github.event.pull_request.draft == false
     runs-on: ubuntu-20.04
     needs:
       - upgrade
diff --git a/.pylintrc b/.pylintrc
index 5bca367a..bc0c538d 100644
--- a/.pylintrc
+++ b/.pylintrc
@@ -2,6 +2,15 @@
 #   pylint --generate-rcfile > .pylintrc_new
 # and compare the output
 
+[BASIC]
+good-names=
+    i,
+    j,
+    k,
+    q,
+    x,
+    _,
+
 [VARIABLES]
 init-import=yes
 
@@ -13,6 +22,7 @@ disable=
     C0330,  # https://github.com/psf/black/issues/48
     RST203, # unexpected indentation
     RST301, # related to google style docstring
+    R0801,  # similar lines # https://github.com/PyCQA/pylint/issues/214
     logging-fstring-interpolation,
     not-callable,
     unused-import,  # https://www.flake8rules.com/rules/F401
diff --git a/commitlint.config.js b/commitlint.config.js
index 1bfd0417..2652860f 100644
--- a/commitlint.config.js
+++ b/commitlint.config.js
@@ -5,6 +5,7 @@ module.exports = {
       2,
       "always",
       [
+        "adr",
         "build",
         "ci",
         "chore",
diff --git a/docs/develop.md b/docs/develop.md
index fbed1abf..c24e81ef 100644
--- a/docs/develop.md
+++ b/docs/develop.md
@@ -581,6 +581,8 @@ The documentation of the `stable` branch is also the default view
 {ref}`you see on Read the Docs <develop:Documentation>` (RTD). See e.g.
 [expertsystem.rtfd.io/en/stable](https://expertsystem.rtfd.io/en/stable).
 
+(master-branch)=
+
 #### `master` branch
 
 Represents the upcoming release of the package. This branch is not guaranteed
@@ -620,10 +622,10 @@ python3 -m pip install git+https://github.com/ComPWA/expertsystem@epic/some-titl
 
 #### Feature branches
 
-The {ref}`develop:master branch` and {ref}`develop:epic branches` can be
-updated through pull requests. It is best to create such a pull request from a
-separate branch, which does not have any CI or code review restrictions. We
-call this a "feature branch".
+The {ref}`master-branch` and {ref}`develop:epic branches` can be updated
+through pull requests. It is best to create such a pull request from a separate
+branch, which does not have any CI or code review restrictions. We call this a
+"feature branch".
 
 ### Commit conventions
 
diff --git a/labels.toml b/labels.toml
index b52063c9..ff39a752 100644
--- a/labels.toml
+++ b/labels.toml
@@ -6,7 +6,7 @@ description = "Something isn't working"
 [Epic]
 color = "3E4B9E"
 name = "Epic"
-description = ""
+description = "Collection of issues, managed by ZenHub"
 
 ["⚠️ Interface"]
 color = "BFDADC"
diff --git a/reqs/3.6/requirements-dev.txt b/reqs/3.6/requirements-dev.txt
index 404a9fae..07b730f3 100644
--- a/reqs/3.6/requirements-dev.txt
+++ b/reqs/3.6/requirements-dev.txt
@@ -8,7 +8,7 @@ alabaster==0.7.12
 anyio==2.1.0
 appdirs==1.4.4
 argon2-cffi==20.1.0
-astroid==2.4.2
+astroid==2.5.0
 async-generator==1.10
 attrs==20.3.0
 babel==2.9.0
@@ -40,13 +40,13 @@ flake8==3.8.4
 gitdb==4.0.5
 gitpython==3.1.13
 graphviz==0.16
-identify==1.5.13
+identify==1.5.14
 idna==2.10
 imagesize==1.2.0
 immutables==0.15
 importlib-metadata==3.4.0
 importlib-resources==3.0.0
-ipykernel==5.4.3
+ipykernel==5.5.0
 ipython-genutils==0.2.0
 ipython==7.16.1
 ipywidgets==7.6.3
@@ -59,17 +59,17 @@ jupyter-cache==0.4.2
 jupyter-client==6.1.11
 jupyter-console==6.2.0
 jupyter-core==4.7.1
-jupyter-server==1.3.0
+jupyter-server==1.4.0
 jupyter-sphinx==0.3.1
 jupyter==1.0.0
 jupyterlab-code-formatter==1.4.4
-jupyterlab-server==2.2.0
+jupyterlab-server==2.3.0
 jupyterlab-widgets==1.0.0
-jupyterlab==3.0.7
+jupyterlab==3.0.8
 kiwisolver==1.3.1
 labels==20.1.0
 latexcodec==2.0.1
-lazy-object-proxy==1.4.3
+lazy-object-proxy==1.5.2
 livereload==2.6.3
 markdown-it-py==0.6.2
 markupsafe==1.1.1
@@ -79,9 +79,9 @@ mdit-py-plugins==0.2.5
 mistune==0.8.4
 mpmath==1.2.1
 mypy-extensions==0.4.3
-mypy==0.800
+mypy==0.812
 myst-nb==0.11.1
-myst-parser==0.13.3
+myst-parser==0.13.5
 nbclassic==0.2.6
 nbclient==0.5.2
 nbconvert==5.6.1
@@ -116,7 +116,7 @@ pydeps==1.9.13
 pydocstyle==5.1.1
 pyflakes==2.2.0
 pygments==2.8.0
-pylint==2.6.0
+pylint==2.7.0
 pyparsing==2.4.7
 pyrsistent==0.17.3
 python-dateutil==2.8.1
@@ -142,7 +142,7 @@ sphinx-math-dollar==1.2
 sphinx-panels==0.5.2
 sphinx-thebe==0.0.8
 sphinx-togglebutton==0.2.3
-sphinx==3.5.0
+sphinx==3.5.1
 sphinxcontrib-applehelp==1.0.2
 sphinxcontrib-bibtex==2.1.4
 sphinxcontrib-devhelp==1.0.2
@@ -157,7 +157,7 @@ terminado==0.9.2
 testpath==0.4.4
 toml==0.10.2
 tornado==6.1
-tox==3.21.4
+tox==3.22.0
 traitlets==4.3.3
 typed-ast==1.4.2
 typing-extensions==3.7.4.3
diff --git a/reqs/3.6/requirements-doc.txt b/reqs/3.6/requirements-doc.txt
index cd674ed3..876f9dbb 100644
--- a/reqs/3.6/requirements-doc.txt
+++ b/reqs/3.6/requirements-doc.txt
@@ -29,7 +29,7 @@ idna==2.10
 imagesize==1.2.0
 importlib-metadata==3.4.0
 importlib-resources==3.0.0
-ipykernel==5.4.3
+ipykernel==5.5.0
 ipython-genutils==0.2.0
 ipython==7.16.1
 ipywidgets==7.6.3
@@ -52,7 +52,7 @@ mdit-py-plugins==0.2.5
 mistune==0.8.4
 mpmath==1.2.1
 myst-nb==0.11.1
-myst-parser==0.13.3
+myst-parser==0.13.5
 nbclient==0.5.2
 nbconvert==5.6.1
 nbdime==2.1.0
@@ -94,7 +94,7 @@ sphinx-math-dollar==1.2
 sphinx-panels==0.5.2
 sphinx-thebe==0.0.8
 sphinx-togglebutton==0.2.3
-sphinx==3.5.0
+sphinx==3.5.1
 sphinxcontrib-applehelp==1.0.2
 sphinxcontrib-bibtex==2.1.4
 sphinxcontrib-devhelp==1.0.2
diff --git a/reqs/3.6/requirements-sty.txt b/reqs/3.6/requirements-sty.txt
index 0bc71c02..06b190b3 100644
--- a/reqs/3.6/requirements-sty.txt
+++ b/reqs/3.6/requirements-sty.txt
@@ -5,7 +5,7 @@
 #    pip-compile --no-annotate --output-file=reqs/3.6/requirements-sty.txt reqs/3.6/requirements-sty.in
 #
 appdirs==1.4.4
-astroid==2.4.2
+astroid==2.5.0
 attrs==20.3.0
 black==20.8b1
 cfgv==3.2.0
@@ -22,7 +22,7 @@ flake8-builtins==1.5.3
 flake8-polyfill==1.0.2
 flake8-rst-docstrings==0.0.14
 flake8==3.8.4
-identify==1.5.13
+identify==1.5.14
 importlib-metadata==3.4.0
 importlib-resources==3.0.0
 ipython-genutils==0.2.0
@@ -30,11 +30,11 @@ isort==5.7.0
 jsonschema==3.2.0
 jupyter-core==4.7.1
 kiwisolver==1.3.1
-lazy-object-proxy==1.4.3
+lazy-object-proxy==1.5.2
 matplotlib==3.3.4
 mccabe==0.6.1
 mypy-extensions==0.4.3
-mypy==0.800
+mypy==0.812
 nbformat==5.1.2
 nbstripout==0.3.9
 nodeenv==1.5.0
@@ -46,7 +46,7 @@ pre-commit==2.10.1
 pycodestyle==2.6.0
 pydocstyle==5.1.1
 pyflakes==2.2.0
-pylint==2.6.0
+pylint==2.7.0
 pyparsing==2.4.7
 pyrsistent==0.17.3
 python-dateutil==2.8.1
diff --git a/reqs/3.7/requirements-dev.txt b/reqs/3.7/requirements-dev.txt
index 6dd710f6..c3a86b98 100644
--- a/reqs/3.7/requirements-dev.txt
+++ b/reqs/3.7/requirements-dev.txt
@@ -8,7 +8,7 @@ alabaster==0.7.12
 anyio==2.1.0
 appdirs==1.4.4
 argon2-cffi==20.1.0
-astroid==2.4.2
+astroid==2.5.0
 async-generator==1.10
 attrs==20.3.0
 babel==2.9.0
@@ -38,11 +38,11 @@ flake8==3.8.4
 gitdb==4.0.5
 gitpython==3.1.13
 graphviz==0.16
-identify==1.5.13
+identify==1.5.14
 idna==2.10
 imagesize==1.2.0
 importlib-metadata==3.4.0
-ipykernel==5.4.3
+ipykernel==5.5.0
 ipython-genutils==0.2.0
 ipython==7.20.0
 ipywidgets==7.6.3
@@ -55,17 +55,17 @@ jupyter-cache==0.4.2
 jupyter-client==6.1.11
 jupyter-console==6.2.0
 jupyter-core==4.7.1
-jupyter-server==1.3.0
+jupyter-server==1.4.0
 jupyter-sphinx==0.3.1
 jupyter==1.0.0
 jupyterlab-code-formatter==1.4.4
-jupyterlab-server==2.2.0
+jupyterlab-server==2.3.0
 jupyterlab-widgets==1.0.0
-jupyterlab==3.0.7
+jupyterlab==3.0.8
 kiwisolver==1.3.1
 labels==20.1.0
 latexcodec==2.0.1
-lazy-object-proxy==1.4.3
+lazy-object-proxy==1.5.2
 livereload==2.6.3
 markdown-it-py==0.6.2
 markupsafe==1.1.1
@@ -75,9 +75,9 @@ mdit-py-plugins==0.2.5
 mistune==0.8.4
 mpmath==1.2.1
 mypy-extensions==0.4.3
-mypy==0.800
+mypy==0.812
 myst-nb==0.11.1
-myst-parser==0.13.3
+myst-parser==0.13.5
 nbclassic==0.2.6
 nbclient==0.5.2
 nbconvert==5.6.1
@@ -112,7 +112,7 @@ pydeps==1.9.13
 pydocstyle==5.1.1
 pyflakes==2.2.0
 pygments==2.8.0
-pylint==2.6.0
+pylint==2.7.0
 pyparsing==2.4.7
 pyrsistent==0.17.3
 python-dateutil==2.8.1
@@ -138,7 +138,7 @@ sphinx-math-dollar==1.2
 sphinx-panels==0.5.2
 sphinx-thebe==0.0.8
 sphinx-togglebutton==0.2.3
-sphinx==3.5.0
+sphinx==3.5.1
 sphinxcontrib-applehelp==1.0.2
 sphinxcontrib-bibtex==2.1.4
 sphinxcontrib-devhelp==1.0.2
@@ -153,7 +153,7 @@ terminado==0.9.2
 testpath==0.4.4
 toml==0.10.2
 tornado==6.1
-tox==3.21.4
+tox==3.22.0
 traitlets==5.0.5
 typed-ast==1.4.2
 typing-extensions==3.7.4.3
diff --git a/reqs/3.7/requirements-doc.txt b/reqs/3.7/requirements-doc.txt
index e40cddbe..9bbe157a 100644
--- a/reqs/3.7/requirements-doc.txt
+++ b/reqs/3.7/requirements-doc.txt
@@ -28,7 +28,7 @@ graphviz==0.16
 idna==2.10
 imagesize==1.2.0
 importlib-metadata==3.4.0
-ipykernel==5.4.3
+ipykernel==5.5.0
 ipython-genutils==0.2.0
 ipython==7.20.0
 ipywidgets==7.6.3
@@ -51,7 +51,7 @@ mdit-py-plugins==0.2.5
 mistune==0.8.4
 mpmath==1.2.1
 myst-nb==0.11.1
-myst-parser==0.13.3
+myst-parser==0.13.5
 nbclient==0.5.2
 nbconvert==5.6.1
 nbdime==2.1.0
@@ -93,7 +93,7 @@ sphinx-math-dollar==1.2
 sphinx-panels==0.5.2
 sphinx-thebe==0.0.8
 sphinx-togglebutton==0.2.3
-sphinx==3.5.0
+sphinx==3.5.1
 sphinxcontrib-applehelp==1.0.2
 sphinxcontrib-bibtex==2.1.4
 sphinxcontrib-devhelp==1.0.2
diff --git a/reqs/3.7/requirements-sty.txt b/reqs/3.7/requirements-sty.txt
index 88fa703e..02180ef1 100644
--- a/reqs/3.7/requirements-sty.txt
+++ b/reqs/3.7/requirements-sty.txt
@@ -5,7 +5,7 @@
 #    pip-compile --no-annotate --output-file=reqs/3.7/requirements-sty.txt reqs/3.7/requirements-sty.in
 #
 appdirs==1.4.4
-astroid==2.4.2
+astroid==2.5.0
 attrs==20.3.0
 black==20.8b1
 cfgv==3.2.0
@@ -20,18 +20,18 @@ flake8-builtins==1.5.3
 flake8-polyfill==1.0.2
 flake8-rst-docstrings==0.0.14
 flake8==3.8.4
-identify==1.5.13
+identify==1.5.14
 importlib-metadata==3.4.0
 ipython-genutils==0.2.0
 isort==5.7.0
 jsonschema==3.2.0
 jupyter-core==4.7.1
 kiwisolver==1.3.1
-lazy-object-proxy==1.4.3
+lazy-object-proxy==1.5.2
 matplotlib==3.3.4
 mccabe==0.6.1
 mypy-extensions==0.4.3
-mypy==0.800
+mypy==0.812
 nbformat==5.1.2
 nbstripout==0.3.9
 nodeenv==1.5.0
@@ -43,7 +43,7 @@ pre-commit==2.10.1
 pycodestyle==2.6.0
 pydocstyle==5.1.1
 pyflakes==2.2.0
-pylint==2.6.0
+pylint==2.7.0
 pyparsing==2.4.7
 pyrsistent==0.17.3
 python-dateutil==2.8.1
diff --git a/reqs/3.8/requirements-dev.txt b/reqs/3.8/requirements-dev.txt
index 49dd2dc8..2c83ebad 100644
--- a/reqs/3.8/requirements-dev.txt
+++ b/reqs/3.8/requirements-dev.txt
@@ -8,7 +8,7 @@ alabaster==0.7.12
 anyio==2.1.0
 appdirs==1.4.4
 argon2-cffi==20.1.0
-astroid==2.4.2
+astroid==2.5.0
 async-generator==1.10
 attrs==20.3.0
 babel==2.9.0
@@ -38,11 +38,11 @@ flake8==3.8.4
 gitdb==4.0.5
 gitpython==3.1.13
 graphviz==0.16
-identify==1.5.13
+identify==1.5.14
 idna==2.10
 imagesize==1.2.0
 importlib-metadata==3.4.0
-ipykernel==5.4.3
+ipykernel==5.5.0
 ipython-genutils==0.2.0
 ipython==7.20.0
 ipywidgets==7.6.3
@@ -55,17 +55,17 @@ jupyter-cache==0.4.2
 jupyter-client==6.1.11
 jupyter-console==6.2.0
 jupyter-core==4.7.1
-jupyter-server==1.3.0
+jupyter-server==1.4.0
 jupyter-sphinx==0.3.1
 jupyter==1.0.0
 jupyterlab-code-formatter==1.4.4
-jupyterlab-server==2.2.0
+jupyterlab-server==2.3.0
 jupyterlab-widgets==1.0.0
-jupyterlab==3.0.7
+jupyterlab==3.0.8
 kiwisolver==1.3.1
 labels==20.1.0
 latexcodec==2.0.1
-lazy-object-proxy==1.4.3
+lazy-object-proxy==1.5.2
 livereload==2.6.3
 markdown-it-py==0.6.2
 markupsafe==1.1.1
@@ -75,9 +75,9 @@ mdit-py-plugins==0.2.5
 mistune==0.8.4
 mpmath==1.2.1
 mypy-extensions==0.4.3
-mypy==0.800
+mypy==0.812
 myst-nb==0.11.1
-myst-parser==0.13.3
+myst-parser==0.13.5
 nbclassic==0.2.6
 nbclient==0.5.2
 nbconvert==5.6.1
@@ -112,7 +112,7 @@ pydeps==1.9.13
 pydocstyle==5.1.1
 pyflakes==2.2.0
 pygments==2.8.0
-pylint==2.6.0
+pylint==2.7.0
 pyparsing==2.4.7
 pyrsistent==0.17.3
 python-dateutil==2.8.1
@@ -138,7 +138,7 @@ sphinx-math-dollar==1.2
 sphinx-panels==0.5.2
 sphinx-thebe==0.0.8
 sphinx-togglebutton==0.2.3
-sphinx==3.5.0
+sphinx==3.5.1
 sphinxcontrib-applehelp==1.0.2
 sphinxcontrib-bibtex==2.1.4
 sphinxcontrib-devhelp==1.0.2
@@ -153,7 +153,7 @@ terminado==0.9.2
 testpath==0.4.4
 toml==0.10.2
 tornado==6.1
-tox==3.21.4
+tox==3.22.0
 traitlets==5.0.5
 typed-ast==1.4.2
 typing-extensions==3.7.4.3
diff --git a/reqs/3.8/requirements-doc.txt b/reqs/3.8/requirements-doc.txt
index 6ea00df0..3fc341a5 100644
--- a/reqs/3.8/requirements-doc.txt
+++ b/reqs/3.8/requirements-doc.txt
@@ -28,7 +28,7 @@ graphviz==0.16
 idna==2.10
 imagesize==1.2.0
 importlib-metadata==3.4.0
-ipykernel==5.4.3
+ipykernel==5.5.0
 ipython-genutils==0.2.0
 ipython==7.20.0
 ipywidgets==7.6.3
@@ -51,7 +51,7 @@ mdit-py-plugins==0.2.5
 mistune==0.8.4
 mpmath==1.2.1
 myst-nb==0.11.1
-myst-parser==0.13.3
+myst-parser==0.13.5
 nbclient==0.5.2
 nbconvert==5.6.1
 nbdime==2.1.0
@@ -93,7 +93,7 @@ sphinx-math-dollar==1.2
 sphinx-panels==0.5.2
 sphinx-thebe==0.0.8
 sphinx-togglebutton==0.2.3
-sphinx==3.5.0
+sphinx==3.5.1
 sphinxcontrib-applehelp==1.0.2
 sphinxcontrib-bibtex==2.1.4
 sphinxcontrib-devhelp==1.0.2
diff --git a/reqs/3.8/requirements-sty.txt b/reqs/3.8/requirements-sty.txt
index e587a948..8d27c9de 100644
--- a/reqs/3.8/requirements-sty.txt
+++ b/reqs/3.8/requirements-sty.txt
@@ -5,7 +5,7 @@
 #    pip-compile --no-annotate --output-file=reqs/3.8/requirements-sty.txt reqs/3.8/requirements-sty.in
 #
 appdirs==1.4.4
-astroid==2.4.2
+astroid==2.5.0
 attrs==20.3.0
 black==20.8b1
 cfgv==3.2.0
@@ -20,17 +20,17 @@ flake8-builtins==1.5.3
 flake8-polyfill==1.0.2
 flake8-rst-docstrings==0.0.14
 flake8==3.8.4
-identify==1.5.13
+identify==1.5.14
 ipython-genutils==0.2.0
 isort==5.7.0
 jsonschema==3.2.0
 jupyter-core==4.7.1
 kiwisolver==1.3.1
-lazy-object-proxy==1.4.3
+lazy-object-proxy==1.5.2
 matplotlib==3.3.4
 mccabe==0.6.1
 mypy-extensions==0.4.3
-mypy==0.800
+mypy==0.812
 nbformat==5.1.2
 nbstripout==0.3.9
 nodeenv==1.5.0
@@ -42,7 +42,7 @@ pre-commit==2.10.1
 pycodestyle==2.6.0
 pydocstyle==5.1.1
 pyflakes==2.2.0
-pylint==2.6.0
+pylint==2.7.0
 pyparsing==2.4.7
 pyrsistent==0.17.3
 python-dateutil==2.8.1
diff --git a/reqs/3.9/requirements-dev.txt b/reqs/3.9/requirements-dev.txt
index d7102e0d..cbb745f7 100644
--- a/reqs/3.9/requirements-dev.txt
+++ b/reqs/3.9/requirements-dev.txt
@@ -8,7 +8,7 @@ alabaster==0.7.12
 anyio==2.1.0
 appdirs==1.4.4
 argon2-cffi==20.1.0
-astroid==2.4.2
+astroid==2.5.0
 async-generator==1.10
 attrs==20.3.0
 babel==2.9.0
@@ -38,11 +38,11 @@ flake8==3.8.4
 gitdb==4.0.5
 gitpython==3.1.13
 graphviz==0.16
-identify==1.5.13
+identify==1.5.14
 idna==2.10
 imagesize==1.2.0
 importlib-metadata==3.4.0
-ipykernel==5.4.3
+ipykernel==5.5.0
 ipython-genutils==0.2.0
 ipython==7.20.0
 ipywidgets==7.6.3
@@ -55,17 +55,17 @@ jupyter-cache==0.4.2
 jupyter-client==6.1.11
 jupyter-console==6.2.0
 jupyter-core==4.7.1
-jupyter-server==1.3.0
+jupyter-server==1.4.0
 jupyter-sphinx==0.3.1
 jupyter==1.0.0
 jupyterlab-code-formatter==1.4.4
-jupyterlab-server==2.2.0
+jupyterlab-server==2.3.0
 jupyterlab-widgets==1.0.0
-jupyterlab==3.0.7
+jupyterlab==3.0.8
 kiwisolver==1.3.1
 labels==20.1.0
 latexcodec==2.0.1
-lazy-object-proxy==1.4.3
+lazy-object-proxy==1.5.2
 livereload==2.6.3
 markdown-it-py==0.6.2
 markupsafe==1.1.1
@@ -75,9 +75,9 @@ mdit-py-plugins==0.2.5
 mistune==0.8.4
 mpmath==1.2.1
 mypy-extensions==0.4.3
-mypy==0.800
+mypy==0.812
 myst-nb==0.11.1
-myst-parser==0.13.3
+myst-parser==0.13.5
 nbclassic==0.2.6
 nbclient==0.5.2
 nbconvert==5.6.1
@@ -112,7 +112,7 @@ pydeps==1.9.13
 pydocstyle==5.1.1
 pyflakes==2.2.0
 pygments==2.8.0
-pylint==2.6.0
+pylint==2.7.0
 pyparsing==2.4.7
 pyrsistent==0.17.3
 python-dateutil==2.8.1
@@ -138,7 +138,7 @@ sphinx-math-dollar==1.2
 sphinx-panels==0.5.2
 sphinx-thebe==0.0.8
 sphinx-togglebutton==0.2.3
-sphinx==3.5.0
+sphinx==3.5.1
 sphinxcontrib-applehelp==1.0.2
 sphinxcontrib-bibtex==2.1.4
 sphinxcontrib-devhelp==1.0.2
@@ -153,7 +153,7 @@ terminado==0.9.2
 testpath==0.4.4
 toml==0.10.2
 tornado==6.1
-tox==3.21.4
+tox==3.22.0
 traitlets==5.0.5
 typed-ast==1.4.2
 typing-extensions==3.7.4.3
diff --git a/reqs/3.9/requirements-doc.txt b/reqs/3.9/requirements-doc.txt
index 038de447..ac7d750b 100644
--- a/reqs/3.9/requirements-doc.txt
+++ b/reqs/3.9/requirements-doc.txt
@@ -28,7 +28,7 @@ graphviz==0.16
 idna==2.10
 imagesize==1.2.0
 importlib-metadata==3.4.0
-ipykernel==5.4.3
+ipykernel==5.5.0
 ipython-genutils==0.2.0
 ipython==7.20.0
 ipywidgets==7.6.3
@@ -51,7 +51,7 @@ mdit-py-plugins==0.2.5
 mistune==0.8.4
 mpmath==1.2.1
 myst-nb==0.11.1
-myst-parser==0.13.3
+myst-parser==0.13.5
 nbclient==0.5.2
 nbconvert==5.6.1
 nbdime==2.1.0
@@ -93,7 +93,7 @@ sphinx-math-dollar==1.2
 sphinx-panels==0.5.2
 sphinx-thebe==0.0.8
 sphinx-togglebutton==0.2.3
-sphinx==3.5.0
+sphinx==3.5.1
 sphinxcontrib-applehelp==1.0.2
 sphinxcontrib-bibtex==2.1.4
 sphinxcontrib-devhelp==1.0.2
diff --git a/reqs/3.9/requirements-sty.txt b/reqs/3.9/requirements-sty.txt
index bef9f4d6..7e1c6aab 100644
--- a/reqs/3.9/requirements-sty.txt
+++ b/reqs/3.9/requirements-sty.txt
@@ -5,7 +5,7 @@
 #    pip-compile --no-annotate --output-file=reqs/3.9/requirements-sty.txt reqs/3.9/requirements-sty.in
 #
 appdirs==1.4.4
-astroid==2.4.2
+astroid==2.5.0
 attrs==20.3.0
 black==20.8b1
 cfgv==3.2.0
@@ -20,17 +20,17 @@ flake8-builtins==1.5.3
 flake8-polyfill==1.0.2
 flake8-rst-docstrings==0.0.14
 flake8==3.8.4
-identify==1.5.13
+identify==1.5.14
 ipython-genutils==0.2.0
 isort==5.7.0
 jsonschema==3.2.0
 jupyter-core==4.7.1
 kiwisolver==1.3.1
-lazy-object-proxy==1.4.3
+lazy-object-proxy==1.5.2
 matplotlib==3.3.4
 mccabe==0.6.1
 mypy-extensions==0.4.3
-mypy==0.800
+mypy==0.812
 nbformat==5.1.2
 nbstripout==0.3.9
 nodeenv==1.5.0
@@ -42,7 +42,7 @@ pre-commit==2.10.1
 pycodestyle==2.6.0
 pydocstyle==5.1.1
 pyflakes==2.2.0
-pylint==2.6.0
+pylint==2.7.0
 pyparsing==2.4.7
 pyrsistent==0.17.3
 python-dateutil==2.8.1
diff --git a/tox.ini b/tox.ini
index a1605ac1..b3610ad6 100644
--- a/tox.ini
+++ b/tox.ini
@@ -66,20 +66,10 @@ allowlist_externals =
     mypy
     pre-commit
 commands =
-    mypy src .  # run separately because of potential caching problems
+    mypy src tests  # run separately because of potential caching problems
     pre-commit run {posargs} -a
     - bash -ec "cspell --no-progress $(git ls-files)"
 
-[testenv:upgrade]
-description =
-    Upgrade pinned dependencies for native Python version
-allowlist_externals =
-    bash
-deps =
-    pip-tools
-commands =
-    bash reqs/upgrade.sh
-
 [flake8]
 application-import-names =
     pwa_pages
@@ -89,6 +79,7 @@ filename =
 exclude =
     __pycache__
     docs/conf.py
+    typings/**
 ignore = # more info: https://www.flake8rules.com/
     E203 # https://github.com/psf/black#slices
     E231 # allowed by black