We introduce results of computer experiments on information processing in a
hexagonal array of vesicles filled with Belousov-Zhabotinsky (BZ) solution in a
sub-excitable mode. We represent values of Boolean variables by excitation
wave-fragments and implement basic logical gates by colliding the
wave-fragments. We show that a vesicle filled with BZ mixture can implement a
range of basic logical functions. We cascade BZ-vesicle logical gates into
arithmetic circuits implementing addition of two one-bit binary numbers. We
envisage that our theoretical results will be applied in chemical laboratory
designs of massive-parallel computers based on fine-grained
compartmentalisation of excitable chemical systems