Calculus (from Latin calculus meaning ‘pebble’, plural calculī) in its most general sense is any method or system of calculation. Calculus may refer to: Biology Calculus (spider), a genus of the family Oonopidae Caseolus calculus, a genus and species of small land snails Mathematics Infinitesimal calculus (or simply Calculus), which investigate motion and rates of change Differential calculus Integral calculus Non-standard calculus, an approach to infinitesimal calculus using Robinson's infinitesimals Calculus of sums and differences (difference operator), also called the finite-difference calculus, a discrete analogue of "calculus" Functional calculus, a way to apply various types of functions to operators Schubert calculus, a branch of algebraic geometry Tensor calculus (also called tensor analysis), a generalization of vector calculus that encompasses tensor fields Vector calculus (also called vector analysis), comprising specialized notations for multivariable analysis of vectors in an inner-product space Matrix calculus, a specialized notation for multivariable calculus over spaces of matrices Numerical calculus (also called numerical analysis), the study of numerical approximations Umbral calculus, the combinatorics of certain operations on polynomials The calculus of variations, a field of study that deals with extremizing functionals Itô calculus An extension of calculus to stochastic processes. Logic Logical calculus, a formal system that defines a language and rules to derive an expression from premises Propositional calculus, specifies the rules of inference governing the logic of propositions Predicate calculus, specifies the rules of inference governing the logic of predicates Proof calculus, a framework for expressing systems of logical inference Sequent calculus, a proof calculus for first-order logic Cirquent calculus, a proof calculus based on graph-style structures called cirquents Situation calculus, a framework for describing relations within a dynamic system Event calculus, a model for reasoning about events and their effects Fluent calculus, a model for describing relations within a dynamic system Calculus of relations, the manipulation of binary relations with the algebra of sets, composition of relations, and transpose relations Epsilon calculus, a logical language which replaces quantifiers with the epsilon operator Fitch-style calculus, a method for constructing formal proofs used in first-order logic Modal μ-calculus, a common temporal logic used by formal verification methods such as model checking Medicine Calculus (dental), deposits of calcium phosphate salts on teeth, also known as tartar Calculus (medicine), a stone formed in the body such as a gall stone or kidney stone Physics Bondi k-calculus, a method used in relativity theory Jones calculus, used in optics to