Adaptive Code Refinement grammar. The ACR grammar declares simple to use language extensions for approximate computing. The alternative defines a modification of the code to express various approximate blocks or statements. The strategy links these alternatives to a constant value for adaptive selection and applies them globally or restricted to an area when defined at compile time. The monitor serves as the link between the functions that pre-process and compute the strategy values at runtime and the data used to take a decision. The grid defines the granularity at which the decision is made. In the case where the granularity is more than one, the folding function is used to map multiple decision values into a single one for the whole cell.