adding representation of empty clauses #337

	name: CI

	on: [push, pull_request]

	jobs:
	build:
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v3
	- name: setup
	run: rustup default 1.72 && rustup component add clippy
	- name: lint
	run: cargo clippy --version && cargo clippy --all-targets --all-features --tests --no-deps -- -D warnings
	- name: build
	run: cargo --version && cargo build
	test:
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v3
	- name: setup
	run: rustup default 1.72
	- name: test
	run: cargo --version && cargo test --release
	format:
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v3
	- name: setup
	run: rustup default 1.72 && rustup component add rustfmt
	- name: check formatting
	run: cargo fmt --version && cargo fmt --check

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