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Date: 29-7-2021
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Definition: Let X and Y be topological spaces. A function h: X → Y is said to be a homeomorphism if and only if the following conditions are satisfied:
• the function h: X → Y is both injective and surjective (so that the function h: X → Y has a well-defined inverse h−1: Y → X),
• the function h: X → Y and its inverse h−1: Y → X are both continuous.
Two topological spaces X and Y are said to be homeomorphic if there exists a homeomorphism h: X → Y from X to Y .
If h: X → Y is a homeomorphism between topological spaces X and Y then h induces a one-to-one correspondence between the open sets of X and the open sets of Y . Thus the topological spaces X and Y can be regarded as being identical as topological spaces.
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علامات بسيطة في جسدك قد تنذر بمرض "قاتل"
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أول صور ثلاثية الأبعاد للغدة الزعترية البشرية
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قسم الشؤون الفكرية والثقافية يجري اختبارات مسابقة حفظ دعاء أهل الثغور
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