Functional programming has its roots in lambda calculus, a formal system developed in the 1930s to investigate computability, the Entscheidungsproblem, function definition, function application, and recursion. Many functional programming languages can be viewed as elaborations on the lambda calculus.
The sternum or breastbone is a long flat bone shaped like a necktie located in the center of the chest. It connects to the ribs via cartilage, forming the front of the rib cage, and thus helps to protect the heart, lungs, and major blood vessels from injury. The sternum consists of three regions: the manubrium, the body, and the xiphoid process.
Sternum pain is a sharp, usually unexpected pain in the chest area. The pain is sometimes associated with myocardial infarction (MI) or heart attack because of the similar sharp pain felt by the sufferer. Sternum pain is characterized by a radiating paineither in the inferior side or sides of the breast bone. In certain cases, the pain is accompanied with tenderness and swelling accompanied by a cracking sound from the sternum joints. Such a condition is referred to as popping sternum.