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Hello students, assume that i is an ideal of a lie algebra l.
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Consider the coset space l by i formed by the cosets of i.
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Define the projection map pi such that l to l by i such that pi of x equal to x plus i for all x in l.
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This is a lie algebra homomorphism.
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The kernel of pi is the set of all elements x in l such that pi of x equal to x plus i equal to i.
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This means x belongs to i.
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X belongs to i.
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So, the kernel of pi is i.
02:06
Kernel of pi is i.
02:10
Hence, the subset i is the kernel of the lie algebra homomorphism pi.
02:33
Next, assume that i is the kernel of lie algebra homomorphism pi such that l to m between lie algebras l and m.
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This means that for all x, y in l, pi of x, y is equal to pi of x, y in m and pi of i is equal to 0 of m where 0 is the element of m...