Dynamically self-checked or fault-tolerant realizations of switching functions and sequential machines are proposed under a fault model that permits arbitrary logic faults in a single-logic module, where the modules are explicitly defined. These realizations permit considerable logic sharing, organized around an (n, m, r)-basis for decomposing switching functions. The logic sharing permits more economical realizations than can be obtained using classical parity and triple-modular redundancy schemes for obtaining logic circuits with the corresponding property.