  Unification of logic variables instantly connects present and future
observations of their value, independently of their location in the data areas
of the runtime system. The paper extends this property to "interclausal logic
variables", an easy to implement Prolog extension that supports instant global
information exchanges without dynamic database updates. We illustrate their
usefulness with two of algorithms, {\em graph coloring} and {\em minimum
spanning tree}. Implementations of interclausal variables as source-level
transformations and as abstract machine adaptations are given. To address the
need for globally visible chained transitions of logic variables we describe a
DCG-based program transformation that extends the functionality of interclausal
variables.
