Silogismo Disyuntivo

Razonamiento 'o/o': O bien A o bien B, no A, por lo tanto B.

Aprender

Razonamiento 'o/o': O bien A o bien B, no A, por lo tanto B.

Disjunctive Syllogism is a rule of inference that eliminates alternatives. Given that 'Either A or B' is true (at least one must hold), and knowing that A is false, we can conclude that B must be true. This is also called 'process of elimination' and is fundamental to decision-making and proof by cases.

P ∨ Q, ¬P ⊢ Q

Either the package was delivered or it was lost. It was not delivered. Therefore, it was lost.
Either the answer is 42 or 56. The answer is not 42. Therefore, the answer is 56.
Either John took the bus or he walked. John did not take the bus. Therefore, John walked.

Cómo reconocerlo

Look for an 'Either...or...' statement (disjunction)
One of the options is ruled out (negated)
The conclusion affirms the remaining option

Errores comunes

Assuming 'Either A or B' means exactly one is true (exclusive or). In logic, 'or' typically allows both to be true
Affirming one disjunct does not eliminate the other: 'Either A or B, A is true' does NOT mean B is false

Resolución paso a paso

La respuesta es 42 o 56. La respuesta no es 42. ¿Qué podemos concluir?

Identifica la disyunción: 'O 42 o 56'
Una opción se descarta: 'No 42'
Aplica Silogismo Disyuntivo: si P es falso, Q debe ser verdadero
Concluye: La respuesta es 56

Respuesta: The answer is 56

Orientación para practicar

Deducción Lógica