De Morgan AND-to-OR Negation Transformer

Rewrite a negated conjunction of two identifier atoms using ! for negation and || for disjunction.

Description

De Morgan’s law moves negation across a conjunction by negating each operand and changing the connecting operation.

De Morgan’s law moves negation across a conjunction by negating each operand and changing the connecting operation.1

The tool returns original, rewritten. Interpret the result under the rule and assumptions below; an encoded premise’s truth is not independently established.

When to use De Morgan AND-to-OR Negation Transformer

Use this for the following task: Rewrite a negated conjunction of two identifier atoms using ! for negation and || for disjunction. Prepare the specified logical encoding before running the check or transformation.

How to use De Morgan AND-to-OR Negation Transformer and understand its results

  1. Prepare the requested Boolean values, complete truth-table rows, or identifier atoms. An atom is a name such as p or premise_1, not a natural-language sentence.
  2. Enter p, q according to the field table, then run the tool.
  3. Read original, rewritten. Use the matching rule, assignment order or nonempty-class assumptions below to interpret the result.
  4. For a false check, inspect the supplied encoding and matching rule. A well-formed false result is different from an input error.
Input fieldMeaningValue type and boundsRequirement
pPstring; maximum text length 100; pattern ^(?!(?:true|false)$)[A-Za-z_][A-Za-z0-9_]*$(?![\s\S])Required
qQstring; maximum text length 100; pattern ^(?!(?:true|false)$)[A-Za-z_][A-Za-z0-9_]*$(?![\s\S])Required

Supply identifier atoms p and q. Return the fixed original negated binary expression and the corresponding De Morgan expansion.

NOT(P AND Q) ≡ NOT P OR NOT Q

The symbols and boundary conditions refer to the supplied fields and the implementation described above.

Output fieldMeaningValue type
originalOriginal propositional formulastring (propositional-formula)
rewrittenEquivalent propositional formulastring (propositional-formula)
json
{
  "input": {
    "p": "p",
    "q": "q"
  },
  "output": {
    "original": "!(p && q)",
    "rewritten": "(!p || !q)"
  }
}

Limitations and assumptions

Operands are case-sensitive identifier atoms, not complete expressions. The tool does not parse a proof or determine whether the premises are true.

The supplied encodings must represent the intended propositions or classes. No natural-language parsing or assessment of empirical premise truth is performed. Malformed input gives a tool error rather than a logical false result.

Alternative or Complementary methods

Choose De Morgan OR-to-AND Negation Transformer when you need its operation: Rewrite a negated disjunction of two identifier atoms using ! for negation and && for conjunction. Choose Material Equivalence Expansion Rewriter (P↔Q two forms) for the complementary operation: Expand material equivalence between identifier atoms into the disjunction of their matching truth states.

Background reference: Additional rules for TFL.

References

  1. Additional rules for TFL — forallx Calgary, Open Logic Project

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