REACHER is a tool that derives the conditions under which each program block in a Pascal program, procedure or function may be executed (i.e., the reachability conditions for each subprocedure, subfunction and begin-end block). The tool shall accept compilable Pascal program source code and shall produce both an annotated listing and an augmented control flow graph. REACHER is one of a series of four tools that work in an integrated fashion to analyze Pascal programs to determine the failure regions associated with identified faults in the programs. The augmented control flow graph produced by REACHER will used as input by the programs FALTER and SPACER, and shall be customized for such usage. The annotated source listing provides includes a correspondence between Pascal statements and control flow graph nodes. The users may access REACHER, FALTER and SPACER through a screen-oriented user interface called VIEWER. This document describes the operation of REACHER and its direct user interface.