ag-gipp/GoUldI

<math xmlns="http://www.w3.org/1998/Math/MathML"><mn>4</mn><mfenced close=")" open="("><mrow><msup><mi>η</mi><mn>1</mn></msup><mfenced close=")" open="("><msub><mi>T</mi><mn>1</mn></msub></mfenced><mo>⋅</mo><msup><mi>η</mi><mn>2</mn></msup><mfenced close=")" open="("><msub><mi>T</mi><mn>2</mn></msub></mfenced><mo>-</mo><msup><mi>η</mi><mn>2</mn></msup><mfenced close=")" open="("><msub><mi>T</mi><mn>1</mn></msub></mfenced><mo>⋅</mo><msup><mi>η</mi><mn>1</mn></msup><mfenced close=")" open="("><msub><mi>T</mi><mn>2</mn></msub></mfenced></mrow></mfenced><mo>=</mo><mo>|</mo><msub><mi>T</mi><mn>1</mn></msub><mo>∩</mo><msub><mi>T</mi><mn>2</mn></msub><mo>|</mo></math>