DRAFT: JuMP has multiple types of expressions: affine, quadratic, and nonlinear. Just talk about affine and quadratic here (see other section for nonlinear). Describe the basic data structures and ways to construct expressions (these are: constructors, operators,
add_to_expression!, and macros).
Example code with doc tests:
m = Model() @variable(m, x) @variable(m, y) AffExpr(-1.0, x => 2.0, y => 1.0) # output 2 x + y - 1
TODO: Describe how JuMP expressions relate to MOI functions. How to set, query, and modify an objective function.