modal-logic
100 / 100 · Low risk
Fine to try.
Extending propositional and predicate logic with modal operators -- necessity and possibility, and their relatives (obligation, knowledge, belief, time). Covers Kripke possible-worlds semantics, accessibility relations, the main modal systems (K, T, S4, S5), translation from natural language, and applications in epistemic, deontic, and temporal reasoning. Use when ordinary logic is insufficient to capture distinctions like "must" vs "might," "knows" vs "believes," "always" vs "sometimes."
What this skill can do
We found nothing in the files we read that matches our rules. That does not prove the skill is safe: see the limits of static scanning.
Install
Paste this into your terminal. It downloads exactly the version we scanned, not whatever is newest.
if [ -e ~/.agents/skills/'modal-logic' ] || [ -L ~/.agents/skills/'modal-logic' ]; then echo 'A skill folder named modal-logic already exists — not replacing it' >&2; false; else d=$(mktemp -d) && git clone --quiet --filter=blob:none --no-checkout 'https://github.com/Tibsfox/gsd-skill-creator' "$d" && git -C "$d" checkout --quiet 'e179dfe911f3b3c2ff8bcd90ecd6ee4738648d17' -- 'examples/skills/logic/modal-logic' && mkdir -p ~/.agents/skills && cp -R "$d"/'examples/skills/logic/modal-logic' ~/.agents/skills/'modal-logic' && rm -rf "$d"; fi
Codex reads ~/.agents/skills directly. For Claude Code, Cursor, Copilot, Gemini CLI, Antigravity or OpenCode, also link it. For Claude Code: ln -s ~/.agents/skills/'modal-logic' ~/.claude/skills/'modal-logic' (other agents: ~/.cursor/skills, ~/.copilot/skills, ~/.gemini/skills, ~/.gemini/config/skills, ~/.config/opencode/skills). Or install through the finder skill, which does both.
Badge for your README
[](https://zalavijaysinh.github.io/skilltrust/repos/Tibsfox/gsd-skill-creator/)
Score history
| Date | Version | Score |
|---|---|---|
| 2026-11-07 | e179dfe | 100 |