Endospores are hardy, defensive structures that enable some bacteria to survive harmful environmental conditions, such as starvation, high temperatures, desiccation (drying out), chemical disinfectants and extremes in pH.
Recursive formula is a formula that is used to determine the next term of a sequence using one or more of the preceding terms.
A first-order term is recursively constructed from constant symbols, variables and function symbols. An expression formed by applying a predicate symbol to an appropriate number of terms is called an atomic formula, which evaluates to true or false in bivalent logics, given an interpretation.