Create a summation AST node

Constructs an abstract syntax tree (AST) node representing a summation over an index. The index is typically a set, dims or when object if filtering is applied to the index.

Usage

ast_sum(index = ast_dims(), value)

Arguments

index

Character. The index variable (e.g., "t").

value

An AST node representing the expression to be summed.

Value

An object of class ast and sum.