Exercise 7.1.4. Show the following basic properties of \(E\)-local spectra:
- (1)
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A spectrum \(L\) is \(E\)-local if and only if \(\hom (X,L) = 0\) for every \(E\)-acyclic spectrum \(X\);
- (2)
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Given an exact sequence \(X \to Y \to Z\), if two of these three spectra are \(E\)-local then so is the third;
- (3)
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In particular, if \(L\) is \(E\)-local then so are all its shifts \(L[n]\);
- (4)
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A limit \(\lim _i L_i\) of \(E\)-local spectra is \(E\)-local;
- (5)
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A retract of an \(E\)-local spectrum is \(E\)-local.
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