memcpy is trivially modeled as an operation on an underlying store. Such stores are a basic feature of any programming language semantics. Putchar is easily mo

memcpy is trivially modeled as an operation on an underlying store. Such stores are a basic feature of any programming language semantics. Putchar is easily modeled in terms of something like a state monad. In earlier semantics, such as the original denotational semantics, it was just modeled directly as a store that was threaded through a program, i.e. passed to every function. Fork is modeled by process calculi. If you think programming languages somehow can't be modeled by mathematics, you're essentially taking the position that they're doing something supernatural.