In the Tetris version below, a constant bit function seeds the AND chain with 1 (see lower-right).

Since the evaluation order is established by the sequence in which components are built, each input propagates upward as it advances from left-to-right. The diamond arrangement of swap circuits is a consequence of nearly-parallel, diagonally-upward lines that terminate on the vertical AND chain.

There is a variation of the equals function where the parameters are rearranged:

f( [ X, A, B ] ) = [ E, A, B ]

Its circuit is roughly the horizontal-reflection of the one above:

Here is the Tetris realization:

There is a another variation that uses all three input bytes:

f( [ A, B, V ] ) = [ A, B, E ], where V,E ∈ { 0, 1 }

The variation can be realized by using the lowest bit of V as the seed of the AND chain. Instead, in an effort to reuse wherever possible, an AND gate was added to the top of the existing circuit:

The Tetris implementation follows.

The horizontal-reflection of this variation was not implemented.