symmetric monoidal (∞,1)-category of spectra A mathematical structure is essentially algebraic if its definition involves partially defined operations satisfying equational laws, where the domain of any given operation is a subset where various other operations happen to be equal. An actual algebraic theory is one where all operations are total functions. The most familiar example may be the (strict) notion of category: a small category consists of a set of objects, a set of morphisms, source...