typos

Introduction.md

@@ -42,7 +42,7 @@ First of all, some code evaluating projects were found and examined. It's not a
 
 ### CMS
 
-[CMS](http://cms-dev.github.io/index.html) is and opensource distributed system for running and organizing programming contests. It's written in Python and contain several modules. CMS supports C/C++, Pascal, Python, PHP and Java languages. PostgreSQL is sigle point of failure, all modules heavily depends on DB connection. Task evaluation can be only three step pipeline -- compilation, execution, evaluation. Execution is performed in [Isolate](https://github.com/ioi/isolate), sandbox written by consultant of our project, Mgr. Martin Mareš, Ph.D.
+[CMS](http://cms-dev.github.io/index.html) is and opensource distributed system for running and organizing programming contests. It's written in Python and contain several modules. CMS supports C/C++, Pascal, Python, PHP and Java languages. PostgreSQL is single point of failure, all modules heavily depends on DB connection. Task evaluation can be only three step pipeline -- compilation, execution, evaluation. Execution is performed in [Isolate](https://github.com/ioi/isolate), sandbox written by consultant of our project, Mgr. Martin Mareš, Ph.D.
 
 ### MOE
 
@@ -55,7 +55,7 @@ First of all, some code evaluating projects were found and examined. It's not a
 
 ## Survey results
 
-From the survey above, we set up several goals, which a new system should have. They mostly reflect drawbacks of current version of CodEx. No existing tool fits our needs, for example no examined project provides comples execution/evaluation pipelane to support needs of courses like Compiler principles. Modifying existing project is also not an option, because of specific university environment. To sum up, existing CodEx has to be completelly rewritten, with only small parts of adopted code (for example judges).
+From the survey above, we set up several goals, which a new system should have. They mostly reflect drawbacks of current version of CodEx. No existing tool fits our needs, for example no examined project provides complex execution/evaluation pipeline to support needs of courses like Compiler principles. Modifying existing project is also not an option, because of specific university environment. To sum up, existing CodEx has to be completelly rewritten, with only small parts of adopted code (for example judges).
 
 The new project is **ReCodEx - ReCodEx Code Examiner**. The name should point to CodEx, previous evaluation solution, but also reflect new approach to solve issues. **Re** as part of the name means redesigned, rewrited, renewed or restarted.
 
@@ -74,7 +74,7 @@ Official terminology of ReCodEx which will be used in documentation and within c
 
 * **Exercise** - Exercise is basic point of all evaluation. Students are receiving assignment from their teacher, but firstly there has to be authors of exercises from which assignments are derived. Assignment is basically exercise which was assigned to some group of students for evaluation.
 
-* **Assignment** - Teachers are creating assignments from exercises which are solved by students. When assignment is solved then students submit their solution, this solution with all other informations (needed by worker) is called submission.
+* **Assignment** - Teachers are creating assignments from exercises which are solved by students. When assignment is solved then students submit their solution, this solution with all other information (needed by worker) is called submission.
 
 * **Reference solution** - When authors create exercises, they should provide sample solution. This solution should pass all test cases in specified limits. It can be also used for auto-calibration of exercise.