Does Being an Automorphism of L Imply Being an Automorphism of K?

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SUMMARY

In the discussion, it is established that if K is an extension field of L and L is an extension field of F, then an F-automorphism of K is also an F-automorphism of L, confirming that (1) implies (2). Specifically, the automorphism conditions are defined as t(a) = a for all t in G(K, F) and t(a) = a for all t in G(L, F). The reverse implication, that (2) implies (1), is not generally true, highlighting the asymmetry in the relationship between the automorphisms of these fields.

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  • Basic logic and reasoning skills in mathematical proofs.
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chapani
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let K be an extention field of L and L be an extenstion field of F.

(1) t(a)=a ,for all t e G(K,F)

(2) t(a)=a ,for all t e G(L,F)

where e means "belongs to" , G(K,F) means "set of all automorphisms of K

leaving every element of F fixed and similarly for G(L,F).

i would like to know is (2) implies (1) or (1) implies (2)?

i think (2) implies (1) but not sure.[i have used simple logic no.of automorphisms of K =< no.of auto. of L]

if not then please give answer with counter example,if there no relation between

them then explain with reasion.

thanks in advanced for help me
 
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We have ##F \subseteq L \subseteq K## and an ##F-##automorphism of ##K## is automatically an ##F-##automorphism of ##L##, so (1) implies (2). The opposite is not generally true.
 

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