Define ⌈T⌉ = λx.λy.x and ⌈F⌉ = λx.λy.y .

Furthermore,let ⌈if t then u else v⌉ =tuv.

Show ⌈if T then u else v⌉= u and ⌈if F then u else v⌉ = v.

(the proof sustem is Natural Deduction)

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I don't know how to start the proof.

Any help will be appreciated.