"only if" meaning in English

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  "lang": "English",
  "lang_code": "en",
  "pos": "conj",
  "senses": [
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      "derived": [
        {
          "word": "if and only if"
        }
      ],
      "examples": [
        {
          "text": "The company will succeed only if it has sufficient backing."
        },
        {
          "ref": "1611, The Holy Bible, […] (King James Version), London: […] Robert Barker, […], →OCLC, 2 Kings 21:8:",
          "text": "Neither will I make the feet of Israel move any more out of the land which I gave their fathers; only if they will observe to do according to all that I have commanded them, and according to all the law that my servant Moses commanded them.",
          "type": "quote"
        },
        {
          "text": "1965 June 4, John W. Tukey, Data Analysis and the Frontiers of Geophysics, in Science New Series, 148(3675), page 1288, http://links.jstor.org/sici?sici=0036-8075%2819650604%293%3A148%3A3675%3C1283%3ADAATFO%3E2.0.CO%3B2-N\nThis is a somewhat paradoxical conclusion, and we can be happy to learn that it follows only if we can trust, precisely and in detail, the assumed way in which the probability of occurrence of a deviation decreases as the size of that deviation increases."
        },
        {
          "ref": "2005, Ellen Siever, Aaron Weber, Stephen Figgins, Robert Love, Arnold Robbins, Linux in a Nutshell, O'Reilly, page 802:",
          "text": "This option is available only if the client supports it.",
          "type": "quote"
        }
      ],
      "glosses": [
        "Not unless; used to introduce a necessary condition."
      ],
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        [
          "Not",
          "not"
        ],
        [
          "unless",
          "unless"
        ],
        [
          "necessary",
          "necessary"
        ],
        [
          "condition",
          "condition"
        ]
      ],
      "translations": [
        {
          "code": "fi",
          "lang": "Finnish",
          "sense": "not unless",
          "word": "vain, jos"
        },
        {
          "code": "hu",
          "lang": "Hungarian",
          "sense": "not unless",
          "word": "csak akkor"
        },
        {
          "code": "hu",
          "lang": "Hungarian",
          "sense": "not unless",
          "word": "csakis akkor"
        },
        {
          "code": "pl",
          "lang": "Polish",
          "sense": "not unless",
          "word": "tylko jeżeli"
        }
      ]
    }
  ],
  "word": "only if"
}

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    {
      "word": "if and only if"
    }
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  "pos": "conj",
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      "examples": [
        {
          "text": "The company will succeed only if it has sufficient backing."
        },
        {
          "ref": "1611, The Holy Bible, […] (King James Version), London: […] Robert Barker, […], →OCLC, 2 Kings 21:8:",
          "text": "Neither will I make the feet of Israel move any more out of the land which I gave their fathers; only if they will observe to do according to all that I have commanded them, and according to all the law that my servant Moses commanded them.",
          "type": "quote"
        },
        {
          "text": "1965 June 4, John W. Tukey, Data Analysis and the Frontiers of Geophysics, in Science New Series, 148(3675), page 1288, http://links.jstor.org/sici?sici=0036-8075%2819650604%293%3A148%3A3675%3C1283%3ADAATFO%3E2.0.CO%3B2-N\nThis is a somewhat paradoxical conclusion, and we can be happy to learn that it follows only if we can trust, precisely and in detail, the assumed way in which the probability of occurrence of a deviation decreases as the size of that deviation increases."
        },
        {
          "ref": "2005, Ellen Siever, Aaron Weber, Stephen Figgins, Robert Love, Arnold Robbins, Linux in a Nutshell, O'Reilly, page 802:",
          "text": "This option is available only if the client supports it.",
          "type": "quote"
        }
      ],
      "glosses": [
        "Not unless; used to introduce a necessary condition."
      ],
      "links": [
        [
          "Not",
          "not"
        ],
        [
          "unless",
          "unless"
        ],
        [
          "necessary",
          "necessary"
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          "condition",
          "condition"
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  "translations": [
    {
      "code": "fi",
      "lang": "Finnish",
      "sense": "not unless",
      "word": "vain, jos"
    },
    {
      "code": "hu",
      "lang": "Hungarian",
      "sense": "not unless",
      "word": "csak akkor"
    },
    {
      "code": "hu",
      "lang": "Hungarian",
      "sense": "not unless",
      "word": "csakis akkor"
    },
    {
      "code": "pl",
      "lang": "Polish",
      "sense": "not unless",
      "word": "tylko jeżeli"
    }
  ],
  "word": "only if"
}