[FourtySeven]

They don't, the whole doctrine is the result of a willful misunderstanding of the word “estin”.

That's a new one on me. What do you mean by "estin", and how does this affect the dogma of Transubstantiation?

[count-your-change]

Rather than a lengthy explanation I'll suggest going to a Greek/English Interlinear and a Greek/English Lexicon and finally Strong's Concordance.

Those in hand, the word Jesus used for “is” at the memorial meal, in Greek, is “estin”.