What (who) is class variables - definition
KEYWORD FROM THE JAVA PROGRAMMING LANGUAGE
Final class; Java final; Blank final; Final variables in Java
free variable
CLASSIFICATION OF VARIABLES IN A LOGIC FORMULA BASED ON WHETHER OR NOT THEY ARE INSIDE THE SCOPE OF A QUANTIFIER
Free variable; Bound variable; Variable binding operation; Variable-binding operation; Free variables; Bound variables; Unbound variable; Unbound variables; Variable-binding operator; Variable binding operator; Free and bound variables; Bound variable clash; Free and bound variable; Placeholder (computer programming); Free variables & bound variables; Free occurrence; Placeholder variable; Apparent variable
1. A variable referred to in a function, which is not an
argument of the function. In lambda-calculus, x is a {bound
variable} in the term M = x . T, and a free variable of T.
We say x is bound in M and free in T. If T contains a subterm
x . U then x is rebound in this term. This nested, inner
binding of x is said to "shadow" the outer binding.
Occurrences of x in U are free occurrences of the new x.
Variables bound at the top level of a program are technically
free variables within the terms to which they are bound but
are often treated specially because they can be compiled as
fixed addresses. Similarly, an identifier bound to a
recursive function is also technically a free variable within
its own body but is treated specially.
A closed term is one containing no free variables.
See also closure, lambda lifting, scope.
2. In logic, a variable which is not quantified (see
quantifier).
bound variable
CLASSIFICATION OF VARIABLES IN A LOGIC FORMULA BASED ON WHETHER OR NOT THEY ARE INSIDE THE SCOPE OF A QUANTIFIER
Free variable; Bound variable; Variable binding operation; Variable-binding operation; Free variables; Bound variables; Unbound variable; Unbound variables; Variable-binding operator; Variable binding operator; Free and bound variables; Bound variable clash; Free and bound variable; Placeholder (computer programming); Free variables & bound variables; Free occurrence; Placeholder variable; Apparent variable
1. A bound variable or formal argument in a function
definition is replaced by the actual argument when the
function is applied. In the lambda abstraction
x . M
x is the bound variable. However, x is a free variable of
the term M when M is considered on its own. M is the scope
of the binding of x.
2. In logic a bound variable is a quantified variable. See
quantifier.
Exchangeable random variables
SEQUENCE OF RANDOM VARIABLES SUCH THAT, FOR ANY FINITE PERMUTATION OF THE INDICES, THE JOINT PROBABILITY DISTRIBUTION OF THE PERMUTED SEQUENCE EQUALS THAT OF THE ORIGINAL
Exchangeable events; Interchangeable random variables; Exchangeability; Exchangeable sequence; Exchangeable random variable; Exchangeable matrix; Exchangeable correlation matrix
In statistics, an exchangeable sequence of random variables (also sometimes interchangeable) is a sequence X1, X2, X3, ... (which may be finitely or infinitely long) whose joint probability distribution does not change when the positions in the sequence in which finitely many of them appear are altered.
Wikipedia
Final (Java)
In the Java programming language, the final keyword is used in several contexts to define an entity that can only be assigned once.
Once a final variable has been assigned, it always contains the same value. If a final variable holds a reference to an object, then the state of the object may be changed by operations on the object, but the variable will always refer to the same object (this property of final is called non-transitivity). This applies also to arrays, because arrays are objects; if a final variable holds a reference to an array, then the components of the array may be changed by operations on the array, but the variable will always refer to the same array.
