Added to FEATURES.md, and corrected IIS docstring in Highs.h

Author: jajhall

FEATURES.md

@@ -6,10 +6,9 @@ Forcing column reduction now checks the bound on the column dual rather than whe
 
 Now handling correctly the case where an infeasible MIP has a feasible relaxation, so no ray is computed fixing [#2415](https://github.com/ERGO-Code/HiGHS/issues/2415)
 
-Fixed minor bug exposed by [#2441](https://github.com/ERGO-Code/HiGHS/issues/2441) in Highs::setSolution() for a sparse user solution when the moidel is empty, and only clearing the dual data before solving with modified objective in Highs::multiobjectiveSolve() so that user-supplied solution is not cleared.
+Fixed minor bug exposed by [#2441](https://github.com/ERGO-Code/HiGHS/issues/2441) in `Highs::setSolution()` for a sparse user solution when the moidel is empty, and only clearing the dual data before solving with modified objective in `Highs::multiobjectiveSolve()` so that user-supplied solution is not cleared.
 
-
-The irreducible infeasibility system (IIS) facility now detects infeasibility due to bounds on constraint activity values being incompatible with constraint bounds. A kIisStrategyLight mode for the iis_strategy option has been introduced so that only infeasibility due to incompatible variable/constraint bounds and constraint activity values is checked for. The LP corresponding to any known IIS is now formed and held as a data member of the HighsIis class. 
+The irreducible infeasibility system (IIS) facility now detects infeasibility due to bounds on constraint activity values (implied by variable bounds) being incompatible with constraint bounds. A `kIisStrategyLight mode` for the `iis_strategy` option has been introduced so that only infeasibility due to incompatible variable/constraint bounds and constraint activity values is checked for. The LP corresponding to any known IIS is now formed and held as a data member of the `HighsIis` class. It can be obtained as a const reference using `Highs::getIisLp()`, and written to a file using `Highs::writeIisModel(const std::string& filename = "")`
 
 Prompted by [#2463](https://github.com/ERGO-Code/HiGHS/issues/2463), the HiGHS solution and basis files now match data to any column and row names in the model, only assuming that the data are aligned with column and row indices if there are no names in the model. This requires a new version (v2) of the HiGHS basis file. Basis files from v1 are still read, but deprecated. Now, when writing out a model, basis or solution, column and row names are added to the model - previously they were created temporarily and inconsistentyly on the fly. If the model has existing names, then distinctive names are created to replace any blank names, but names with spaces or duplicate names yield an error status return.
 

highs/Highs.h

@@ -434,13 +434,14 @@ class Highs {
                                 double* value = nullptr);
 
   /**
-   * @brief Return a const reference to the presolved HighsLp instance in HiGHS
+   * @brief Return a const reference to the internal presolved HighsLp
+   * instance
    */
   const HighsLp& getPresolvedLp() const { return presolved_model_.lp_; }
 
   /**
-   * @brief Return a const reference to the presolved HighsModel instance in
-   * HiGHS
+   * @brief Return a const reference to the internal presolved
+   * HighsModel instance
    */
   const HighsModel& getPresolvedModel() const { return presolved_model_; }
 
@@ -476,13 +477,13 @@ class Highs {
   const HighsModel& getModel() const { return model_; }
 
   /**
-   * @brief Return a const reference to the internal HighsSolution instance
+   * @brief Return a const reference to the internal HighsSolution
+   * instance
    */
   const HighsSolution& getSolution() const { return solution_; }
 
   /**
-   * @brief Return a const reference to the presolved HighsModel instance in
-   * HiGHS
+   * @brief Return a const reference to the internal IIS LP instance
    */
   const HighsLp& getIisLp() const { return iis_.model_.lp_; }
 
@@ -492,7 +493,8 @@ class Highs {
   void zeroAllClocks() { timer_.zeroAllClocks(); };
 
   /**
-   * @brief Return a const reference to the internal HighsSolution instance
+   * @brief Return a const reference to the internal HighsSolution
+   * instance
    */
   const std::vector<HighsObjectiveSolution>& getSavedMipSolutions() const {
     return saved_objective_and_solution_;
@@ -856,7 +858,7 @@ class Highs {
   HighsStatus writePresolvedModel(const std::string& filename = "");
 
   /**
-   * @brief Write out the IIS model to a file
+   * @brief Write out the internal IIS LP instance to a file
    */
   HighsStatus writeIisModel(const std::string& filename = "");