substituties

Substituties is the plural form of substitution and appears in several disciplines to denote the act of replacing one element with another. The core idea is replacement under defined rules or constraints, producing an equivalent or functionally similar outcome within a system.

In mathematics and logic, substitution is used to replace a variable with an expression, simplify equations, or change variables in integrals. The method of substitution solves systems of equations and can transform integrals into computable forms. Substitution rules rely on maintaining consistency of variables and operations.

In chemistry, substitution refers to substitution reactions in which an atom or group is replaced by another. Common types include nucleophilic and electrophilic substitution, especially on aromatic rings, where a hydrogen or substituent is replaced by another substituent. Substituent effects influence reaction rate and orientation, such as ortho, para, and meta positioning on aromatic systems.

In linguistics and communications, substitution can describe the replacement of a linguistic unit with a stand-in form or pronoun, or the use of canonical placeholder words in analysis. It also appears in phonology as phoneme substitution across dialects or during speech errors.

In information security and computer science, substitution appears in cryptography as substitution ciphers that map plaintext symbols to ciphertext symbols. It also occurs in programming as substitution or macro expansion, replacing identifiers or templates with actual values during compilation or preprocessing. Substituties thus encompass a family of replacement-based techniques across science, engineering, and communication.