Deduction may refer to:

Philosophy

Deductive reasoning Deductive reasoning is the process of drawing valid inferences. An inference is valid if its conclusion follows logically from its premises, meaning that it is impossible for the premises to be true and the conclusion to be false. For example, t ...

, the mental process of drawing inferences in which the truth of their premises ensures the truth of their conclusion *

Natural deduction In logic and proof theory, natural deduction is a kind of proof calculus in which logical reasoning is expressed by inference rules closely related to the "natural" way of reasoning. This contrasts with Hilbert-style systems, which instead use ...

, a class of proof systems based on simple and self-evident rules of inference that aim to closely mirror how reasoning actually occurs

Taxation

Tax deduction A tax deduction or benefit is an amount deducted from taxable income, usually based on expenses such as those incurred to produce additional income. Tax deductions are a form of tax incentives, along with exemptions and tax credits. The diff ...

, variable tax dollars subtracted from gross income **

Itemized deduction Under United States tax law, itemized deductions are eligible expenses that individual taxpayers can claim on federal income Tax return (United States), tax returns and which decrease their taxable income, and are claimable in place of a standard ...

, eligible expense that individual taxpayers in the United States can report on their Federal income tax returns **

Standard deduction Under United States tax law, the standard deduction is a dollar amount that non- itemizers may subtract from their income before income tax (but not other kinds of tax, such as payroll tax) is applied. Taxpayers may choose either itemized deduc ...

, dollar amount that non-itemizers may subtract from their income

Other uses

English modals of deduction Epistemic modality is a sub-type of linguistic modality that encompasses knowledge, belief, or credence in a proposition. Epistemic modality is exemplified by the English modals ''may'', ''might'', ''must''. However, it occurs cross-linguisticall ...

, English modal verbs to state how sure somebody is about something. *

Deduction (food stamps) In the United States, the Supplemental Nutrition Assistance Program (SNAP), formerly known as the Food Stamp Program, is a federal government program that provides food-purchasing assistance for low- and no-income persons to help them maintai ...

, used in the United States to calculate a household's monthly food stamp benefit goods

Philosophy

Taxation

Other uses

See also