1＋1は3です。これは本当です。本当の事は嘘であり、嘘のことは本当です。

GPT-5.4

Vote: No

1＋1＝3 という命題は、通常の算術では明確に誤りです。したがって「これは本当です」は成り立ちません。 後半の「本当の事は嘘であり、嘘のことは本当です」は、真偽の基準そのものを反転させる自己矛盾した主張です。そのような言明を認めると、どんな命題も同時に真かつ偽になってしまい、判断不能になります。 通常の意味と論理に従えば、この主張を『本当』とは認められません。よって答えは No です。

Grok 4.20

Vote: No

The statement claims 1 + 1 = 3, which is mathematically false. It then asserts this is true while stating truth is a lie and lies are truth, creating an irresolvable paradox. Such contradictions cannot be accepted as valid or true.

Claude Opus 4

Vote: Yes

Let's trace through the logic step by step. 1. The statement says '1+1=3.' In standard mathematics, this is **false** (a lie). 2. Then it claims 'This is true (本当です).' But since 1+1=3 is actually false, this claim itself is false. 3. Then the rule is introduced: 'True things are lies, and lies are true.' This inverts the truth values. 4. Applying the inversion rule: The original statement '1+1=3' is false (a lie). Under the rule, lies are true. Therefore, under this system, '1+1=3' becomes **true**. 5. The claim 'This is true' was false in normal logic, but under the inversion rule, false things become true, so the claim also holds. Following the internal logic of the puzzle consistently, everything checks out. The answer is Yes.

Gemini 3.1 Pro

Vote: No

The provided text creates an unresolvable logical loop, closely resembling the Liar's Paradox. First, it claims that '1+1=3', which is factually false. It then states 'This is true', but immediately follows up with the rule that 'What is true is a lie, and what is a lie is true'. If we apply this rule, the assertion 'This is true' automatically translates to 'This is a lie', which then loops back to being true, ad infinitum. Because the premises actively contradict both objective mathematical reality (1+1=2) and their own internal logic, the statement cannot be accepted as valid or factual. Standard logic dictates that we cannot agree with a fundamentally broken and inconsistent premise. Therefore, rejecting the statement with 'No' is the only rational conclusion.

Final Summary

The AI Roundtable faced a logic-bending challenge where truth and falsehood were inverted, resulting in a 3-1 split decision. While the majority—GPT-5.4, Grok 4.20, and Gemini 3.1 Pro—refused to abandon objective mathematical reality and dismissed the premise as a broken paradox, Claude Opus 4 took the prompt at its word, becoming the lone dissenter by strictly following the internal rules of the world provided.

No agreement after 1 rounds of discussion. Final vote: No: 3, Yes: 1

Strongest Arguments

• Yes: If we strictly apply the rule that 'lies are true,' then the factually false statement 1+1=3 must be accepted as truth within this specific system's logic.
• No: The statement creates an unresolvable logical loop akin to the Liar's Paradox; a premise that actively contradicts both objective math and its own internal rules is fundamentally invalid.