An algebraic loop with the Moufang property,

for all

,

,

in the loop, acts as a vector multiplication and division table for unsigned vectors. If

and

, then

; the left-multiplicative inverse is

*.*A Moufang loop is alternative,

, and all groups, which are associative,

, are Moufang loops. If a Moufang loop has

* *elements and

-fold symmetry it can be "folded" to a loop algebra with

-signed vectors having (

) elements. This introduces roots of unity as generalized signs. Real and complex algebras arise when

or

; examples with

are also included here. Unsigned loops operate as algebras over real and complex fields because they can be folded from larger loops with C2 or C4 symmetries. Loop algebras may have divisors of zero, and include non-Abelian (noncommutative) and nonassociative cases.

I define hoops as symmetry-conserving loop algebras, in which the conjugate factors of the table determinant are conserved sizes or symmetries because

(up to a sign). All groups conserve their determinants (Frobenius 1895); some nonassociative (octonionic) loops are also shown here to be hoops. Hoops lead to new mathematical concepts that are developed in this set of Demonstrations—unsigned continuous "primal" numbers (the half-line) are fundamental, generalized signs are created by folding Moufang loops; the "real algebras without divisors of zero" {

,

,

,

} are degenerate mono-sized hoops; vector division-by-zero is eliminated by the creation of symmetry-conserving remainders; zero sizes project results into reduced-symmetry sub-hoops; Abelian hoops have multi-angle polar-duals and multiphase sinusoidal orbits

*;* etc. The Clifford(

,

) anti-commutative algebras are an important subset of hoops; they generalize both geometry and analysis to any number of dimensions; they have

elements that are square roots of unity and

that are fourth roots, together with a pseudoscalar "I" that is an anti-commutative version of

, so neither -1 nor

are unique.

Choose a "name" (there are 73 available, including 46 distinct, non-isomorphic, hoops). The multiplication table (shown in index or symbolic form) and a brief description appear. Some short sizes are shown. If the table is a group, g

*mmnn *is shown—the group is the

entry in the list of groups with

*mm *elements in the GAP group atlas. Two "random" vectors and their product will also appear. Now step some elements (the values wrap round from +9 to -9). The product changes. The

*shapes* (lists of

*sizes* or symmetries) also appear. If

, the table is reported to be conservative.

Some nonassociative Moufang loops, with up to 16 elements and

in their names, are provided. Only a few are conservative. A few counterexamples, with names ending in

or

, are nonconservative loops.

Choose a hoop with several sizes. Adjust

and

until they have different zero sizes. The sizes of

will have both sets of zeros. Hoop algebras conserve these lost symmetries by ejecting "remainders",

, just as particle interactions may create several particles that conserve symmetries.

Hoops have multiplicative inverses

, with

(the unit vector). This is demonstrated by recovering

from

.

splits into partial fractions with sizes as denominators. As zero sizes in multiplicands give the same zeros in the product, they

*project* the result into a subalgebra of reduced symmetry,

*ejecting* remainders if necessary. The zero is factored out of the calculations, and partial fractions with denominators of near zero size are excluded from the inverse. This eliminates division by zero in hoop operations on vectors.

Later Demonstrations show Abelian (commutative) hoops with polar dual formulations that provide powers and roots, and anticommutative Clifford (geometric) algebras that unify many areas of mathematics.