package codex
Install
dune-project
Dependency
Authors
Maintainers
Sources
md5=bc7266a140c6886add673ede90e335d3
sha512=8da42c0ff2c1098c5f9cb2b5b43b306faf7ac93b8f5ae00c176918cee761f249ff45b29309f31a05bbcf6312304f86a0d5a000eb3f1094d3d3c2b9b4c7f5c386
doc/codex.lattices/Lattices/Quadrivalent/index.html
Module Lattices.QuadrivalentSource
The quadrivalent lattice for booleans, with four elements: Bottom, True, False, and Top.
Standard abstraction for booleans; powerset of {true;false}
include Datatype_sig.S with type t = boolean
Any notion of equality is allowed, as long as it is an equivalence relation, and that if a == b, then equal a b.
In a fixpoint iteration of a function \mathcal{F}, previous is the previous element of the fixpoint iteration sequence. The other element is the newly computed (tentative) element, i.e. \mathcal{F}(previous). If the new element is included in previous, true is returned, together with new (the smaller element): the post-fixpoint of \mathcal{F} has been found (further calls to \mathcal{F} can decrease the sequence). Else, the returned element should be used as the next element of the fixpoint iteration sequence; the operator guarantees its convergence. For lattices of finite height, the widening part can just perform an over-approximation of the join; however note that it is not required that the sequence is monotonic.
includes a b holds if b \sqsubseteq a, i.e., b is at least as precise as a.
Widening operator used in fixpoint iteration to enforce convergence.
returns (may_be_false, may_be_true), as defined in of_bools.