diff --git a/.github/workflows/nix-action-8.16-mathcomp2.yml b/.github/workflows/nix-action-8.16-mathcomp2.yml
index 05d9fd2c..d872dcab 100644
--- a/.github/workflows/nix-action-8.16-mathcomp2.yml
+++ b/.github/workflows/nix-action-8.16-mathcomp2.yml
@@ -1677,6 +1677,58 @@ jobs:
       name: Building/fetching current CI target
       run: NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link --argstr bundle "8.16-mathcomp2"
         --argstr job "coq-shell"
+  coq-tactical:
+    needs:
+    - coq
+    runs-on: ubuntu-latest
+    steps:
+    - name: Determine which commit to initially checkout
+      run: "if [ ${{ github.event_name }} = \"push\" ]; then\n  echo \"target_commit=${{
+        github.sha }}\" >> $GITHUB_ENV\nelse\n  echo \"target_commit=${{ github.event.pull_request.head.sha
+        }}\" >> $GITHUB_ENV\nfi\n"
+    - name: Git checkout
+      uses: actions/checkout@v4
+      with:
+        fetch-depth: 0
+        ref: ${{ env.target_commit }}
+    - name: Determine which commit to test
+      run: "if [ ${{ github.event_name }} = \"push\" ]; then\n  echo \"tested_commit=${{
+        github.sha }}\" >> $GITHUB_ENV\nelse\n  merge_commit=$(git ls-remote ${{ github.event.repository.html_url
+        }} refs/pull/${{ github.event.number }}/merge | cut -f1)\n  mergeable=$(git
+        merge --no-commit --no-ff ${{ github.event.pull_request.base.sha }} > /dev/null
+        2>&1; echo $?; git merge --abort > /dev/null 2>&1 || true)\n  if [ -z \"$merge_commit\"\
+        \ -o \"x$mergeable\" != \"x0\" ]; then\n    echo \"tested_commit=${{ github.event.pull_request.head.sha
+        }}\" >> $GITHUB_ENV\n  else\n    echo \"tested_commit=$merge_commit\" >> $GITHUB_ENV\n\
+        \  fi\nfi\n"
+    - name: Git checkout
+      uses: actions/checkout@v4
+      with:
+        fetch-depth: 0
+        ref: ${{ env.tested_commit }}
+    - name: Cachix install
+      uses: cachix/install-nix-action@v30
+      with:
+        nix_path: nixpkgs=channel:nixpkgs-unstable
+    - name: Cachix setup coq-community
+      uses: cachix/cachix-action@v15
+      with:
+        authToken: ${{ secrets.CACHIX_AUTH_TOKEN }}
+        extraPullNames: coq, math-comp
+        name: coq-community
+    - id: stepCheck
+      name: Checking presence of CI target coq-tactical
+      run: "nb_dry_run=$(NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link \\\n   --argstr
+        bundle \"8.16-mathcomp2\" --argstr job \"coq-tactical\" \\\n   --dry-run 2>&1
+        > /dev/null)\necho $nb_dry_run\necho status=$(echo $nb_dry_run | grep \"built:\"\
+        \ | sed \"s/.*/built/\") >> $GITHUB_OUTPUT\n"
+    - if: steps.stepCheck.outputs.status == 'built'
+      name: 'Building/fetching previous CI target: coq'
+      run: NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link --argstr bundle "8.16-mathcomp2"
+        --argstr job "coq"
+    - if: steps.stepCheck.outputs.status == 'built'
+      name: Building/fetching current CI target
+      run: NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link --argstr bundle "8.16-mathcomp2"
+        --argstr job "coq-tactical"
   coqeal:
     needs:
     - coq
diff --git a/.github/workflows/nix-action-8.16.yml b/.github/workflows/nix-action-8.16.yml
index 55facd7e..17517d0d 100644
--- a/.github/workflows/nix-action-8.16.yml
+++ b/.github/workflows/nix-action-8.16.yml
@@ -1734,6 +1734,58 @@ jobs:
       name: Building/fetching current CI target
       run: NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link --argstr bundle "8.16" --argstr
         job "coq-shell"
+  coq-tactical:
+    needs:
+    - coq
+    runs-on: ubuntu-latest
+    steps:
+    - name: Determine which commit to initially checkout
+      run: "if [ ${{ github.event_name }} = \"push\" ]; then\n  echo \"target_commit=${{
+        github.sha }}\" >> $GITHUB_ENV\nelse\n  echo \"target_commit=${{ github.event.pull_request.head.sha
+        }}\" >> $GITHUB_ENV\nfi\n"
+    - name: Git checkout
+      uses: actions/checkout@v4
+      with:
+        fetch-depth: 0
+        ref: ${{ env.target_commit }}
+    - name: Determine which commit to test
+      run: "if [ ${{ github.event_name }} = \"push\" ]; then\n  echo \"tested_commit=${{
+        github.sha }}\" >> $GITHUB_ENV\nelse\n  merge_commit=$(git ls-remote ${{ github.event.repository.html_url
+        }} refs/pull/${{ github.event.number }}/merge | cut -f1)\n  mergeable=$(git
+        merge --no-commit --no-ff ${{ github.event.pull_request.base.sha }} > /dev/null
+        2>&1; echo $?; git merge --abort > /dev/null 2>&1 || true)\n  if [ -z \"$merge_commit\"\
+        \ -o \"x$mergeable\" != \"x0\" ]; then\n    echo \"tested_commit=${{ github.event.pull_request.head.sha
+        }}\" >> $GITHUB_ENV\n  else\n    echo \"tested_commit=$merge_commit\" >> $GITHUB_ENV\n\
+        \  fi\nfi\n"
+    - name: Git checkout
+      uses: actions/checkout@v4
+      with:
+        fetch-depth: 0
+        ref: ${{ env.tested_commit }}
+    - name: Cachix install
+      uses: cachix/install-nix-action@v30
+      with:
+        nix_path: nixpkgs=channel:nixpkgs-unstable
+    - name: Cachix setup coq-community
+      uses: cachix/cachix-action@v15
+      with:
+        authToken: ${{ secrets.CACHIX_AUTH_TOKEN }}
+        extraPullNames: coq, math-comp
+        name: coq-community
+    - id: stepCheck
+      name: Checking presence of CI target coq-tactical
+      run: "nb_dry_run=$(NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link \\\n   --argstr
+        bundle \"8.16\" --argstr job \"coq-tactical\" \\\n   --dry-run 2>&1 > /dev/null)\n
+        echo $nb_dry_run\necho status=$(echo $nb_dry_run | grep \"built:\" | sed \"\
+        s/.*/built/\") >> $GITHUB_OUTPUT\n"
+    - if: steps.stepCheck.outputs.status == 'built'
+      name: 'Building/fetching previous CI target: coq'
+      run: NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link --argstr bundle "8.16" --argstr
+        job "coq"
+    - if: steps.stepCheck.outputs.status == 'built'
+      name: Building/fetching current CI target
+      run: NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link --argstr bundle "8.16" --argstr
+        job "coq-tactical"
   coqeal:
     needs:
     - coq
diff --git a/.github/workflows/nix-action-8.17.yml b/.github/workflows/nix-action-8.17.yml
index 1d4046e3..cee0d28a 100644
--- a/.github/workflows/nix-action-8.17.yml
+++ b/.github/workflows/nix-action-8.17.yml
@@ -1786,6 +1786,58 @@ jobs:
       name: Building/fetching current CI target
       run: NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link --argstr bundle "8.17" --argstr
         job "coq-shell"
+  coq-tactical:
+    needs:
+    - coq
+    runs-on: ubuntu-latest
+    steps:
+    - name: Determine which commit to initially checkout
+      run: "if [ ${{ github.event_name }} = \"push\" ]; then\n  echo \"target_commit=${{
+        github.sha }}\" >> $GITHUB_ENV\nelse\n  echo \"target_commit=${{ github.event.pull_request.head.sha
+        }}\" >> $GITHUB_ENV\nfi\n"
+    - name: Git checkout
+      uses: actions/checkout@v4
+      with:
+        fetch-depth: 0
+        ref: ${{ env.target_commit }}
+    - name: Determine which commit to test
+      run: "if [ ${{ github.event_name }} = \"push\" ]; then\n  echo \"tested_commit=${{
+        github.sha }}\" >> $GITHUB_ENV\nelse\n  merge_commit=$(git ls-remote ${{ github.event.repository.html_url
+        }} refs/pull/${{ github.event.number }}/merge | cut -f1)\n  mergeable=$(git
+        merge --no-commit --no-ff ${{ github.event.pull_request.base.sha }} > /dev/null
+        2>&1; echo $?; git merge --abort > /dev/null 2>&1 || true)\n  if [ -z \"$merge_commit\"\
+        \ -o \"x$mergeable\" != \"x0\" ]; then\n    echo \"tested_commit=${{ github.event.pull_request.head.sha
+        }}\" >> $GITHUB_ENV\n  else\n    echo \"tested_commit=$merge_commit\" >> $GITHUB_ENV\n\
+        \  fi\nfi\n"
+    - name: Git checkout
+      uses: actions/checkout@v4
+      with:
+        fetch-depth: 0
+        ref: ${{ env.tested_commit }}
+    - name: Cachix install
+      uses: cachix/install-nix-action@v30
+      with:
+        nix_path: nixpkgs=channel:nixpkgs-unstable
+    - name: Cachix setup coq-community
+      uses: cachix/cachix-action@v15
+      with:
+        authToken: ${{ secrets.CACHIX_AUTH_TOKEN }}
+        extraPullNames: coq, math-comp
+        name: coq-community
+    - id: stepCheck
+      name: Checking presence of CI target coq-tactical
+      run: "nb_dry_run=$(NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link \\\n   --argstr
+        bundle \"8.17\" --argstr job \"coq-tactical\" \\\n   --dry-run 2>&1 > /dev/null)\n
+        echo $nb_dry_run\necho status=$(echo $nb_dry_run | grep \"built:\" | sed \"\
+        s/.*/built/\") >> $GITHUB_OUTPUT\n"
+    - if: steps.stepCheck.outputs.status == 'built'
+      name: 'Building/fetching previous CI target: coq'
+      run: NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link --argstr bundle "8.17" --argstr
+        job "coq"
+    - if: steps.stepCheck.outputs.status == 'built'
+      name: Building/fetching current CI target
+      run: NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link --argstr bundle "8.17" --argstr
+        job "coq-tactical"
   coqeal:
     needs:
     - coq
diff --git a/.github/workflows/nix-action-8.18.yml b/.github/workflows/nix-action-8.18.yml
index dfec4ea3..04b8be8d 100644
--- a/.github/workflows/nix-action-8.18.yml
+++ b/.github/workflows/nix-action-8.18.yml
@@ -1724,6 +1724,58 @@ jobs:
       name: Building/fetching current CI target
       run: NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link --argstr bundle "8.18" --argstr
         job "coq-shell"
+  coq-tactical:
+    needs:
+    - coq
+    runs-on: ubuntu-latest
+    steps:
+    - name: Determine which commit to initially checkout
+      run: "if [ ${{ github.event_name }} = \"push\" ]; then\n  echo \"target_commit=${{
+        github.sha }}\" >> $GITHUB_ENV\nelse\n  echo \"target_commit=${{ github.event.pull_request.head.sha
+        }}\" >> $GITHUB_ENV\nfi\n"
+    - name: Git checkout
+      uses: actions/checkout@v4
+      with:
+        fetch-depth: 0
+        ref: ${{ env.target_commit }}
+    - name: Determine which commit to test
+      run: "if [ ${{ github.event_name }} = \"push\" ]; then\n  echo \"tested_commit=${{
+        github.sha }}\" >> $GITHUB_ENV\nelse\n  merge_commit=$(git ls-remote ${{ github.event.repository.html_url
+        }} refs/pull/${{ github.event.number }}/merge | cut -f1)\n  mergeable=$(git
+        merge --no-commit --no-ff ${{ github.event.pull_request.base.sha }} > /dev/null
+        2>&1; echo $?; git merge --abort > /dev/null 2>&1 || true)\n  if [ -z \"$merge_commit\"\
+        \ -o \"x$mergeable\" != \"x0\" ]; then\n    echo \"tested_commit=${{ github.event.pull_request.head.sha
+        }}\" >> $GITHUB_ENV\n  else\n    echo \"tested_commit=$merge_commit\" >> $GITHUB_ENV\n\
+        \  fi\nfi\n"
+    - name: Git checkout
+      uses: actions/checkout@v4
+      with:
+        fetch-depth: 0
+        ref: ${{ env.tested_commit }}
+    - name: Cachix install
+      uses: cachix/install-nix-action@v30
+      with:
+        nix_path: nixpkgs=channel:nixpkgs-unstable
+    - name: Cachix setup coq-community
+      uses: cachix/cachix-action@v15
+      with:
+        authToken: ${{ secrets.CACHIX_AUTH_TOKEN }}
+        extraPullNames: coq, math-comp
+        name: coq-community
+    - id: stepCheck
+      name: Checking presence of CI target coq-tactical
+      run: "nb_dry_run=$(NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link \\\n   --argstr
+        bundle \"8.18\" --argstr job \"coq-tactical\" \\\n   --dry-run 2>&1 > /dev/null)\n
+        echo $nb_dry_run\necho status=$(echo $nb_dry_run | grep \"built:\" | sed \"\
+        s/.*/built/\") >> $GITHUB_OUTPUT\n"
+    - if: steps.stepCheck.outputs.status == 'built'
+      name: 'Building/fetching previous CI target: coq'
+      run: NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link --argstr bundle "8.18" --argstr
+        job "coq"
+    - if: steps.stepCheck.outputs.status == 'built'
+      name: Building/fetching current CI target
+      run: NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link --argstr bundle "8.18" --argstr
+        job "coq-tactical"
   coqeal:
     needs:
     - coq
diff --git a/.github/workflows/nix-action-8.19.yml b/.github/workflows/nix-action-8.19.yml
index b7be8d8f..3d4a8242 100644
--- a/.github/workflows/nix-action-8.19.yml
+++ b/.github/workflows/nix-action-8.19.yml
@@ -1642,6 +1642,58 @@ jobs:
       name: Building/fetching current CI target
       run: NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link --argstr bundle "8.19" --argstr
         job "coq-shell"
+  coq-tactical:
+    needs:
+    - coq
+    runs-on: ubuntu-latest
+    steps:
+    - name: Determine which commit to initially checkout
+      run: "if [ ${{ github.event_name }} = \"push\" ]; then\n  echo \"target_commit=${{
+        github.sha }}\" >> $GITHUB_ENV\nelse\n  echo \"target_commit=${{ github.event.pull_request.head.sha
+        }}\" >> $GITHUB_ENV\nfi\n"
+    - name: Git checkout
+      uses: actions/checkout@v4
+      with:
+        fetch-depth: 0
+        ref: ${{ env.target_commit }}
+    - name: Determine which commit to test
+      run: "if [ ${{ github.event_name }} = \"push\" ]; then\n  echo \"tested_commit=${{
+        github.sha }}\" >> $GITHUB_ENV\nelse\n  merge_commit=$(git ls-remote ${{ github.event.repository.html_url
+        }} refs/pull/${{ github.event.number }}/merge | cut -f1)\n  mergeable=$(git
+        merge --no-commit --no-ff ${{ github.event.pull_request.base.sha }} > /dev/null
+        2>&1; echo $?; git merge --abort > /dev/null 2>&1 || true)\n  if [ -z \"$merge_commit\"\
+        \ -o \"x$mergeable\" != \"x0\" ]; then\n    echo \"tested_commit=${{ github.event.pull_request.head.sha
+        }}\" >> $GITHUB_ENV\n  else\n    echo \"tested_commit=$merge_commit\" >> $GITHUB_ENV\n\
+        \  fi\nfi\n"
+    - name: Git checkout
+      uses: actions/checkout@v4
+      with:
+        fetch-depth: 0
+        ref: ${{ env.tested_commit }}
+    - name: Cachix install
+      uses: cachix/install-nix-action@v30
+      with:
+        nix_path: nixpkgs=channel:nixpkgs-unstable
+    - name: Cachix setup coq-community
+      uses: cachix/cachix-action@v15
+      with:
+        authToken: ${{ secrets.CACHIX_AUTH_TOKEN }}
+        extraPullNames: coq, math-comp
+        name: coq-community
+    - id: stepCheck
+      name: Checking presence of CI target coq-tactical
+      run: "nb_dry_run=$(NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link \\\n   --argstr
+        bundle \"8.19\" --argstr job \"coq-tactical\" \\\n   --dry-run 2>&1 > /dev/null)\n
+        echo $nb_dry_run\necho status=$(echo $nb_dry_run | grep \"built:\" | sed \"\
+        s/.*/built/\") >> $GITHUB_OUTPUT\n"
+    - if: steps.stepCheck.outputs.status == 'built'
+      name: 'Building/fetching previous CI target: coq'
+      run: NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link --argstr bundle "8.19" --argstr
+        job "coq"
+    - if: steps.stepCheck.outputs.status == 'built'
+      name: Building/fetching current CI target
+      run: NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link --argstr bundle "8.19" --argstr
+        job "coq-tactical"
   coqeal:
     needs:
     - coq
diff --git a/.github/workflows/nix-action-8.20.yml b/.github/workflows/nix-action-8.20.yml
index 73f6720d..879a1dff 100644
--- a/.github/workflows/nix-action-8.20.yml
+++ b/.github/workflows/nix-action-8.20.yml
@@ -1238,6 +1238,58 @@ jobs:
       name: Building/fetching current CI target
       run: NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link --argstr bundle "8.20" --argstr
         job "coq-shell"
+  coq-tactical:
+    needs:
+    - coq
+    runs-on: ubuntu-latest
+    steps:
+    - name: Determine which commit to initially checkout
+      run: "if [ ${{ github.event_name }} = \"push\" ]; then\n  echo \"target_commit=${{
+        github.sha }}\" >> $GITHUB_ENV\nelse\n  echo \"target_commit=${{ github.event.pull_request.head.sha
+        }}\" >> $GITHUB_ENV\nfi\n"
+    - name: Git checkout
+      uses: actions/checkout@v4
+      with:
+        fetch-depth: 0
+        ref: ${{ env.target_commit }}
+    - name: Determine which commit to test
+      run: "if [ ${{ github.event_name }} = \"push\" ]; then\n  echo \"tested_commit=${{
+        github.sha }}\" >> $GITHUB_ENV\nelse\n  merge_commit=$(git ls-remote ${{ github.event.repository.html_url
+        }} refs/pull/${{ github.event.number }}/merge | cut -f1)\n  mergeable=$(git
+        merge --no-commit --no-ff ${{ github.event.pull_request.base.sha }} > /dev/null
+        2>&1; echo $?; git merge --abort > /dev/null 2>&1 || true)\n  if [ -z \"$merge_commit\"\
+        \ -o \"x$mergeable\" != \"x0\" ]; then\n    echo \"tested_commit=${{ github.event.pull_request.head.sha
+        }}\" >> $GITHUB_ENV\n  else\n    echo \"tested_commit=$merge_commit\" >> $GITHUB_ENV\n\
+        \  fi\nfi\n"
+    - name: Git checkout
+      uses: actions/checkout@v4
+      with:
+        fetch-depth: 0
+        ref: ${{ env.tested_commit }}
+    - name: Cachix install
+      uses: cachix/install-nix-action@v30
+      with:
+        nix_path: nixpkgs=channel:nixpkgs-unstable
+    - name: Cachix setup coq-community
+      uses: cachix/cachix-action@v15
+      with:
+        authToken: ${{ secrets.CACHIX_AUTH_TOKEN }}
+        extraPullNames: coq, math-comp
+        name: coq-community
+    - id: stepCheck
+      name: Checking presence of CI target coq-tactical
+      run: "nb_dry_run=$(NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link \\\n   --argstr
+        bundle \"8.20\" --argstr job \"coq-tactical\" \\\n   --dry-run 2>&1 > /dev/null)\n
+        echo $nb_dry_run\necho status=$(echo $nb_dry_run | grep \"built:\" | sed \"\
+        s/.*/built/\") >> $GITHUB_OUTPUT\n"
+    - if: steps.stepCheck.outputs.status == 'built'
+      name: 'Building/fetching previous CI target: coq'
+      run: NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link --argstr bundle "8.20" --argstr
+        job "coq"
+    - if: steps.stepCheck.outputs.status == 'built'
+      name: Building/fetching current CI target
+      run: NIXPKGS_ALLOW_UNFREE=1 nix-build --no-out-link --argstr bundle "8.20" --argstr
+        job "coq-tactical"
   coqeal:
     needs:
     - coq
diff --git a/.nix/nixpkgs.nix b/.nix/nixpkgs.nix
index 7ec95f14..3709f129 100644
--- a/.nix/nixpkgs.nix
+++ b/.nix/nixpkgs.nix
@@ -1,4 +1,4 @@
 fetchTarball {
-    url = "https://github.com/NixOS/nixpkgs/archive/d337b780d0469c31c8bc756be3ee52240a3c2f4b.tar.gz";
-    sha256 = "0m9lh7024qb3pppsn1hnk9r4ifgiwd7s365fdza145vngd5nb2na";
+    url = "https://github.com/NixOS/nixpkgs/archive/19ab97dfada0904de0ff1329d93f6bbadf8269f3.tar.gz";
+    sha256 = "13nd774xpivdlsyaqf1079z6qlky10pqrdl8gfd66irw63xs9qn3";
   }