I am actually trying to reproduce the research paper on "Elementary gates for Quantum computation". With reference to that paper, According to Corollary 7.4 - On an n-bit network(where n>=7), a lambda(n-2)[sigma x] gate can be simulated by 8(n-5) lambda(2)[sigma x] gates(3 bit Toffoli gates), as well as by 48n - 204 basic operations. I am able to solve the first part of the corollary. In the 2nd part they say that out of the (8n-40) Toffoli gates, 4 gates can be simulated by 16 basic operations and the remaining (8n-36) gates can be simulated by 6 basic operations. But (4 + (8n-36)) when added does not give 8n-40. That is one part of my doubt. Another thing is that, what do they mean by basic operations?