In mathematical logic, in particular in connection with proof theory, a
number of substructural logics have been introduced, as systems of
propositional calculus that are weaker than the conventional one. They
differ in having fewer structural rules available: the concept of structural
rule is based on the sequent presentation, rather than the natural
deduction formulation. Two of the more significant substructural logics are
relevant logic and linear logic. In the philosophy of language, a natural language (or ordinary language)
is any language which arises in an unpremeditated fashion as the result of
the innate facility for language possessed by the human intellect.
Wyrd is a concept in Old English and Old Norse culture roughly
corresponding to sacred, fate, karma, or synchronicity. The word is
ancestral to Modern English weird, which has acquired a very different
definition.
Spontaneous order is the spontaneous emergence of order out of
seeming chaos; the emergence of various kinds of social order from a
combination of self-interested individuals who are not intentionally trying
to create order. The evolution of life on Earth, language, Wikipedia, and a
free market economy have all been proposed as examples of systems
which evolved through spontaneous order.
Stigmergy is a form of self-organization. It produces complex, apparently
intelligent structures, without need for any planning, control, or even
communication between the agents. As such it supports efficient
collaboration between extremely simple agents, who lack any memory,
intelligence or even awareness of each other.
The types of presumption includes a rebuttable discretionary
presumption, a rebuttable mandatory presumption, and an irrebutable or
conclusive presumption.