Function table_bases 

pub fn table_bases() -> Program

Key loading, step 2: the 54 table bases 2^offset(i) * P of an affine point P = (x, y) (inputs 0, 1), as projective X, Y, Z, T, in digit order (output 4i + c, counted by the controller).

Every output uses indices 0..4; the controller tells bases apart by counting outputs, which arrive in program order.