dsh-boolean

Boolean algebra toolbox for DeepSeek Harness (dsh). Parse propositional-logic expressions and get full truth tables with minterm/maxterm summaries, canonical DNF/CNF, NNF, and NAND-only / NOR-only gate networks — no hand-drawn 16-row tables, no De Morgan slips.

Zero runtime dependencies, pure local math.

Why

Modeled reasoning often derails on small logic chores: expanding ¬(a∧b), listing the satisfying rows of a 3-variable expression, or checking whether two formulas say the same thing. These tools do the bookkeeping exactly, one expression at a time.

Install

dsh plugin --profile web add github:TYEclipse/dsh-boolean

Restart the profile session (or start a new one) and the four tools are registered under tools for every agent. Requires pnpm on PATH (the plugin host resolves it).

Tools

Tool	What it does
truth_table	Enumerates every assignment row (up to 8 variables / 256 rows) with the result, minterm & maxterm indices, tautology / contradiction / satisfiability flags, and canonical DNF and CNF strings.
logic_eval	Evaluates an expression under one complete assignment (trueVars / falseVars); missing variables are reported, never silently defaulted.
logic_equiv	Compares two expressions over all rows of the combined table; reports how many rows differ and one concrete counterexample when they are not equivalent.
logic_convert	Converts an expression to nnf, dnf, cnf, nand, or nor canonical form. DNF/CNF come from the truth table (8-variable cap); nnf/nand/nor are structural rewrites without a cap.

Expression syntax

Meaning	Symbols	Words	Unicode
NOT (prefix)	!	not	¬
AND	&	and	∧
XOR	^	xor	⊕
OR	|	or	∨
IMPLIES	-> =>	implies	→
IFF	<-> <=>	iff	↔

• Variables are single letters a–z (upper case is normalized); parentheses () group.
• Precedence, high to low: NOT → AND → XOR → OR → IMPLIES → IFF.
• Binary operators are left-associative; parenthesize chains of -> / <-> when in doubt.
• XOR, IMPLIES and IFF are desugared at parse time to NOT/AND/OR with the textbook identities (a^b ≡ (a&!b)|(!a&b), a->b ≡ !a|b, a<->b ≡ (a&b)|(!a&!b)).
• Expressions are limited to 512 characters; truth-table enumeration to 8 variables.

Examples

All outputs below are real tool output (v0.1.0).

Truth table of XOR — every row plus the canonical forms:

truth_table { expr: "a ^ b" }
→ rows: m0(00)=0, m1(01)=1, m2(10)=1, m3(11)=0
  minterms [1,2]  DNF = (!a & b) | (a & !b)
  maxterms [0,3]  CNF = (a | b) & (!a | !b)

Check one row instead of the whole table:

logic_eval { expr: "a -> (b | c)", trueVars: ["a"], falseVars: ["b","c"] }
→ a -> (b | c) with a=true, b=false, c=false = false

Verify a rewrite identity (De Morgan):

logic_equiv { exprA: "!(a | b)", exprB: "!a & !b" }
→ equivalent: !(a | b) == !a & !b (all 4 rows agree)

Push negations down or build single-gate networks:

logic_convert { expr: "!(a & b)", operation: "nnf" } → !a | !b
logic_convert { expr: "a & b",   operation: "nand" } → NAND(NAND(a,b),NAND(a,b))
logic_convert { expr: "a | b",   operation: "nor"  } → NOR(NOR(a,b),NOR(a,b))
logic_convert { expr: "a -> b",  operation: "dnf"  } → (!a & !b) | (!a & b) | (a & b)

Invalid input is reported with a position and a reason instead of a wrong answer: a & → unexpected end of expression (at position 3); foo & a → variables must be single letters a–z.

Notes & limits

• Truth-table tools cap at 8 variables (256 rows); nnf/nand/nor conversions are structural and unlimited.
• logic_eval needs every expression variable in exactly one of trueVars / falseVars; listing a variable in both, or a variable name outside a–z, is an error.
• Gate outputs use function-call syntax: NAND(a,b) / NOR(a,b), with NOT(x) written as NAND(x,x) or NOR(x,x). Input grammar does not accept gate names — convert, don't write gates.
• Canonical DNF of a contradiction and canonical CNF of a tautology are the empty string, with an explanatory note.

Development

pnpm install
pnpm build      # tsc -> dist/ (committed: git installs do not build)
pnpm test       # 99 tests: parser semantics, oracle-anchored tables (independent Python
                # enumeration), gate networks, schema guards, lossless-JSON discipline
pnpm lint       # oxlint src test

Test anchors are generated by an independent Python oracle (itertools brute-force truth enumeration + textbook canonical-form construction); every DNF/CNF string and every truth row in the fixture is cross-checked against the TypeScript implementation.

License

MIT — see LICENSE.