# entailment

CEFR C1 · Noun

Source: https://englishreference.com/word/entailment
Updated: 2026-09-28

## Definition

a relationship between two statements where if the first statement is true, the second statement must also be true.

For teachers: a formal semantic or logical relation wherein the truth of one proposition guarantees the truth of another in all possible interpretations.

## Examples

- Saying you own a dog carries the entailment that you own an animal.
- Natural language inference benchmarks test whether an AI can accurately classify sentence pairs into entailment, contradiction, or neutral.
- Automated theorem provers construct proof trees by verifying that each intermediate lemma satisfies the strict criteria of semantic entailment.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.