When the T1 which constitutes an A glider finally makes contact with a C glider, it adds its height, which is 2, to the T1's in the C margin. The result is a shift in the indices of the C, decrementing them except at the discontinuity at C1, which enlarges the C1's T6 to a T7, which transforms the C1 into an F. As long as the effect is shifting, there is no restriction on the spacing between successive A's. From then on, the spacing matters, due to the internal structure of the F or any subsequent intermediaries.
Any spacing at all is possible between A's, from zero onwards, leading to innumerable sequences of A gliders. Two arrangements occur often enough to examine them separately and give them names. The term polymerpolymer, or more specifically monomer, dimer, trimer, ... refers to a cluster of T1's without any spacing at all. On the other hand, polyadpolyad, as in monad, dyad, triad, ... contemplates streams of T1's separated by one single ether tile.