Full Adder Majority Carry Expression Checker

Compute the Boolean sum and majority carry bits of a full adder with a carry input.

Description

A full adder adds two bits and a carry-in.

A full adder adds two bits and a carry-in. The outgoing carry is true when a majority of the three inputs are true.1

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

When to use Full Adder Majority Carry Expression Checker

Use this for the following task: Compute the Boolean sum and majority carry bits of a full adder with a carry input. Prepare the specified logical encoding before running the check or transformation.

How to use Full Adder Majority Carry Expression Checker 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 a, b, carryIn according to the field table, then run the tool.
  3. Read sum, carryOut. 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
aAbooleanRequired
bBbooleanRequired
carryInCarry InbooleanRequired

Supply three Booleans. Convert them to zero or one, sum them and return parity and the carry threshold flag.

total=a+b+carryIn; sum=total mod 2; carryOut=total≥2

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

Output fieldMeaningValue type
sumSumboolean
carryOutCarry Outboolean
json
{
  "input": {
    "a": true,
    "b": true,
    "carryIn": true
  },
  "output": {
    "sum": true,
    "carryOut": true
  }
}

Limitations and assumptions

The result is one ideal bit position. Wiring, propagation delay and multi-bit cascading are outside this calculation.

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 Half Adder Sum Carry Boolean Pair Checker when you need its operation: Compute the Boolean sum and carry bits of a half adder. Choose XOR Definition Expansion (¬P∧Q)∨(P∧¬Q) Checker for the complementary operation: Evaluate XOR and its classical conjunction/disjunction expansion on two Boolean inputs.

Background reference: Complete truth tables.

References

  1. Complete truth tables — forallx Calgary, Open Logic Project

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