An algebraic structure whose elements consist of selected homeomorphisms between open subsets of a space, with the composition of two transformations defined on the largest possible domain. The "germs" of the elements of a pseudogroup form a groupoid (Weinstein 1996).
Pseudogroup
See also
Group, Groupoid, Inverse SemigroupExplore with Wolfram|Alpha
References
Weinstein, A. "Groupoids: Unifying Internal and External Symmetry." Not. Amer. Math. Soc. 43, 744-752, 1996.Referenced on Wolfram|Alpha
PseudogroupCite this as:
Weisstein, Eric W. "Pseudogroup." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/Pseudogroup.html