vormivõrduv

Vormivõrduv, often translated as "form-equivalent" or "shape-congruent," is a concept in Estonian mathematics and logic. It describes a specific type of relationship between two objects, typically geometric figures or logical propositions. The core idea is that while two entities might not be identical in every aspect, they share a fundamental structural equivalence that allows them to be interchanged or mapped onto each other under certain transformations or interpretations.

In geometry, vormivõrduv can refer to figures that are congruent. Congruent figures are identical in shape and size; one can be transformed into the other through a sequence of rigid motions like translations, rotations, and reflections. For example, two squares of the same side length are vormivõrduv. More broadly, it can also encompass similarity, where figures have the same shape but possibly different sizes. In this case, one figure is a scaled version of the other.

In logic and set theory, vormivõrduv can describe propositions that have the same logical structure or sets that have the same cardinality. Two logical statements are considered vormivõrduv if they can be shown to be equivalent through logical deduction, meaning they are true or false under the same conditions. Similarly, two sets are vormivõrduv if there exists a bijection (a one-to-one correspondence) between their elements, indicating they have the same number of elements. The precise meaning of vormivõrduv can vary slightly depending on the specific field of study, but the underlying principle of structural or form-based equivalence remains consistent.