fix typo in README.md

README.md

@@ -54,7 +54,7 @@ Consequently, there is some code replication between implementations.
 
 By convention each AC-OPF stand-alone file implements a function called `solve_opf` that requires one argument, `file_name`. The argument should be a path to an AC-OPF case file that is compatible with PowerModels' `parse_file` function (usually a [MATPOWER](https://matpower.org/) case file). The `solve_opf` function parses the case file, builds the suitable AC-OPF optimization problem, solves it with Ipopt (or the next-best available algorithm) and returns a dictionary of basic information about the solution process. This dictionary includes items such as,
 - `case`: the name of the file that was solved
-- `feasible`: if the modeling layer determined the solution at the competition of the solve process stratifies the model constraints 
+- `feasible`: if the modeling layer determined the solution at the competition of the solve process satisfies the model constraints 
 - `cost`: evaluation of the objective function at the competition of the solve process
 - `time_total`: the total wall-clock time of the `solve_opf` function in seconds