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micronemesis
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let X and X' be two single sets in two topologies T and T' respectively.A standard textbook asks to show that if identity function i:X' →X is continuous then T' is finer than T.Is the example below a valid counter example to this argument?
Homework Equations
3. The example goes like this .Consider γ={1,2,3,4,5} and T={∅,γ,{1,2},{1},{3},{1,2,3},{1,3}} and T'={∅,γ,{1},{1,4}}.X={1,2} and X'={1}.so the subspace topology on X due to T i.e Tx={∅,X,{1}} and T'x'={∅,X'}.It is obvious that inverse of each open element in X' is open in X, but T' is not finer than T.
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