All articles starting with F
15,892 articles
Form follows function
Form follows function is a principle of design and architecture, coined by Louis Sullivan in 1896, holding that a building's shape should derive from its intended purpose.
Form I-140
Form I-140, Immigrant Petition for Alien Worker, is the petition filed with USCIS to classify a foreign worker for an employment-based immigrant visa, generally filed by the U.S. employer.
Form I-9
Form I-9, the Employment Eligibility Verification form, is the form U.S. employers must complete for each employee hired after November 6, 1986, to verify identity and work authorization.
Form I-94
Form I-94 is the Arrival/Departure Record issued by U.S. Customs and Border Protection to foreign travelers admitted to the United States, recording their class of admission and authorized length of stay.
Form W-2
Form W-2 (Wage and Tax Statement) is the US IRS form employers file with the Social Security Administration and give employees, reporting annual wages and federal income, social security, and Medicare tax withheld; distinct from Form 1099 for nonemployees.
Form W-4
Form W-4, Employee's Withholding Certificate, is the IRS form employees give employers to set federal income tax withholding; redesigned for 2020 to drop withholding allowances after the TCJA, with five steps, an exemption option, and a 2026 update adding tips, overtime, and seniors deduction lines.
Form W-9
Form W-9, Request for Taxpayer Identification Number and Certification, is an IRS form a U.S. person uses to give a payer their TIN (SSN, ITIN, EIN) and certifications; it goes to the requester, not the IRS, and supports 1099 reporting and backup withholding at 24%.
Form-closed cam
A form-closed cam is a cam mechanism in which the follower is held on the cam profile by the cam's geometry, typically a groove, instead of by a spring.
FORMA Therapeutics
FORMA Therapeutics was a clinical-stage biopharmaceutical company in Watertown, Massachusetts, developing small-molecule drugs for sickle cell disease and cancers; Novo Nordisk acquired it in 2022 for $1.1 billion.
Formação da Literatura Brasileira
Formação da Literatura Brasileira: momentos decisivos is a 1959 two-volume work of literary history by the Brazilian critic and sociologist Antonio Candido, a foundational text of Brazilian literary historiography.
Formal charge
Formal charge is the hypothetical charge assigned to an atom in a Lewis structure, calculated as if bonding electrons were shared equally regardless of electronegativity.
Formal concept analysis
Formal concept analysis is a mathematical method that derives a hierarchy of concepts, in the form of a lattice, from an object–attribute data table, used in data mining and ontology engineering.
Formal equivalence checking
Formal equivalence checking is a formal verification method that mathematically proves two circuit designs, such as golden RTL and a synthesized netlist, behave identically for all inputs.
Formal fallacy
A formal fallacy is an invalid pattern in a deductive argument, detectable from logical form alone, unlike informal fallacies. Standard examples are affirming the consequent and denying the antecedent; the study of fallacies originates in Aristotle's Sophistical Refutations.
Formal grammar
A formal grammar (grammar formalism) is a finite set of rewriting rules that generates the strings of a formal language, classifying syntax in the Chomsky hierarchy.
Formal language
A formal language is a possibly infinite set of finite strings over an alphabet, defined purely by form rather than meaning, usually specified by a formal grammar such as a context-free grammar.
Formal power series
A formal power series is an infinite sum whose coefficients lie in a fixed ring, treated as an algebraic object without asking whether it converges.
Formal scheme
A formal scheme is an algebraic geometry object built from the formal spectrum Spf(A) of a complete adic ring, retaining infinitesimal information to all orders.
Formal science
A formal science is a discipline, such as mathematics, logic, and theoretical computer science, that establishes its claims by proof within defined symbolic systems rather than by experiment.
Formal Social Control
Formal social control: regulation of behavior through written laws, official rules, and sanctions by institutions such as legislatures, police, courts, and prisons, contrasted with informal control via community norms; MeSH descriptor D012926, introduced 1968.
Formal specification
A formal specification is a description of what a system should do, written in a language with mathematically defined syntax and semantics, so correctness can be checked by proof.
Formal synthesis
A formal synthesis is a chemical synthesis ending at a known intermediate previously converted into the desired target, whose published final steps complete the route.
Formal system
A formal system, or formal logical system, is a set of axioms and inference rules for generating theorems, with proofs checkable mechanically; it underlies Gödel's incompleteness theorems.
Formal verification
Formal verification is a family of mathematical techniques in computer science that prove a system satisfies a formal specification, chiefly through model checking and theorem proving.
Formal wear
Formal wear: clothing prescribed for ceremonies, courts, and evening events, descending from European court dress. Key forms include judicial robes, white tie, and black tie, codified from the 1635 Judges' Rules onward.
Formaldehyde
Formaldehyde, also known as methanal, is the simplest aldehyde, a colorless, flammable gas with a pungent odor used mainly to make resins for wood, paper, and textiles.
Formalin fixation
Formalin fixation preserves tissue by immersing it in dilute formaldehyde, which cross-links proteins and nucleic acids so microscopic structure, antigens, and biomolecules survive storage, staining, and molecular testing.
Formalin test
The formalin test is a rodent pain assay in which dilute formalin is injected into a paw, producing a biphasic pain response used to screen analgesic drugs.
Formalism (art)
Formalism (art): theory and method holding that an artwork's value lies in formal, directly sensible properties like line, color, and composition. Key figures: Clive Bell, Wölfflin, Riegl, Clement Greenberg; critics include Danto and Schapiro.
Formalism (literature)
Formalism (literature): Russian Formalism (1915–1929, OPOJAZ, Moscow Linguistic Circle; Shklovsky, Jakobson) and Anglo-American New Criticism (Brooks, Ransom, Wimsatt), text-autonomous schools analyzing literariness, defamiliarization, and close reading rather than author or context.