mekso operator (binary): projection function; the Bth term/entry ("element") of tuple A
A must be a tuple. Let L = length(A); then L is a positive integer, 0, or infinity (countable), and A = (A_1, A_2, ..., A_L), and B must be a natural number and belong to the ordered interval [1, L]. If L = 0, the output is a placeholder "blank element"; else, if B does not satisfy the aforementioned condition, then the function is undefined. Using the aforementioned notation, and letting Proj represent the projection function, Proj(A, B) = A_B; note that B = 1 will cause the output of the first entry in the tuple, which is A_1. For any i, there is no restriction on the typing/value of A_i so long as it is defined; the type of A_i need not even match the type of A_j for i =/= j. See also: bai'ei, no'au'au, pi'ei. Notice that the input is a single tuple and an integer, it does not rely on anyou underlying stucture; this is markedly different from a the dot product of vectors, although by establishing a basis and an underlying field, they can look quite similar.