There are as many kinds of labyrinth as there are dimensions in which to design them (excepting the first dimension alone, which permits only a binary and trivial variation). The 2-dimensional labyrinth is, of course, the simplest non-trivial variety. Of the 2-dimensional labyrinths, there are two kinds; linear and non-linear. 2-dimensional, linear labyrinths include only four directions; south, east, north, and west. Non-linear labyrinths are omni-directional (throughout 360 degrees).
A 'simple labyrinth' is any 2-dimensional linear labyrinth.
A 'true labyrinth' has only one exit, and therefore one non-trivial solution.
A labyrinth's 'direction-value' (DV) is the number which denotes the total orientation of its solution. A right turn equals +1 to the DV. A left turn equals -1 to the DV. Hence, if a labyrinth's solution necessitates 5 right-turns and 3 left-turns, its DV equals 2.
An 'open labyrinth' has its exit on the periphery of the labyrinth. This kind of labyrinth always has a DV of -1, 0, or 1.
A 'closed labyrinth' has an end-point that is enclosed within the perimeter of the labyrinth. A closed labyrinth is not necessarily direction-neutral.
The fundamental, or "1st order", elements of simple labyrinths can be laid out and enumerated such that each element corresponds to a number of the hexadecimal system (fig. 1):
With this system of labeling, any simple labyrinth can be described numerically with a matrix. For example, the following simple labyrinth (fig. 2) can be described with the corresponding matrix (fig. 3). This matrix can be written as follows: 326/451/035.
Simple labyrinths are modular; that is, larger matrices can be reduced to smaller matrices, or even single numbers. For example, fig. 3 can be reduced to 'c' because fig. 2 is reducible to a north-facing dead-end. However, the DV of a given labyrinth is not affected by modular reduction: Every fundamental dead-end has a DV of zero, whereas fig. 2 has a DV of -4.
Reörienting every labyrinth so that the initial orientation is north (i.e. the entrance always faces south), and fully modulating it to its most fundamental solution, we can see that every simple open true labyrinth can be reduced to 1, 3, or 6. Every simple closed true labyrinth can be reduced to 'c'.
There are elements composed of 1st order elements, called "2nd order" elements. The 2nd order elements are 'loops' and 'trees'. Both loops and trees can be open or closed.
A loop is any pattern which leads back to its initial point. Examples are 36/75 for a closed loop and 36/b5 for a closed loop.
A tree is any pattern which diverts to multiple paths (i.e. branches) from one path. E.g. a/b.
3rd order elements are composed of 2nd order elements. The 3rd order elements are 'wheels' and 'double loops'.
A wheel is a conjunction of trees, such that there are multiple branches in all four directions from a single point. E.g. bb/bb.
A double loop is a loop circumscribed by a loop.