A Proposed Language for the Definition of Arbitrary Twodimensional Signs

According to Ch. S. Peirce [7], we consider a sign s to be an element of a triadic relation, $$\text{s = (m,}\,\text{o,}\,\text{i)}\,\varepsilon \,\text{M} \times \text{O} \times \text{I}\text{.}$$