Added Lots of Documentation

Added some nice to haves
Improved and Unified General Code Layout

MathKit/MPEvaluationContext.m

@@ -8,13 +8,21 @@
 
 #import "MPEvaluationContext.h"
 
+
+
 @interface MPEvaluationContext ()
+
 @property (nonatomic, strong) NSMutableArray *stack;
+
 @end
 
+
+
 @implementation MPEvaluationContext
 
 static MPEvaluationContext *sharedContext;
+
+
 + (MPEvaluationContext *)sharedContext
 {
     if (!sharedContext) {
@@ -23,6 +31,7 @@ static MPEvaluationContext *sharedContext;
     return sharedContext;
 }
 
+
 - (instancetype)init
 {
     if (sharedContext) {
@@ -40,16 +49,19 @@ static MPEvaluationContext *sharedContext;
     return self;
 }
 
+
 - (void)push
 {
     [self.stack addObject:[[NSMutableDictionary alloc] init]];
 }
 
+
 - (void)pop
 {
     [self.stack removeLastObject];
 }
 
+
 - (BOOL)defineVariable:(NSString *)variable
                  value:(NSDecimalNumber *)value
 {
@@ -62,17 +74,20 @@ static MPEvaluationContext *sharedContext;
     return YES;
 }
 
+
 - (void)undefineVariable:(NSString *)variable
 {
     NSMutableDictionary *currentBindings = self.stack.lastObject;
     [currentBindings removeObjectForKey:variable];
 }
 
+
 - (BOOL)isVariableDefined:(NSString *)variable
 {
     return [self valueForVariable:variable] != nil;
 }
 
+
 - (NSDecimalNumber *)valueForVariable:(NSString *)variable
 {
     NSUInteger currentIndex = self.stack.count;