started with SOS, bit tricky with symbols..

HOME_EXAM.md

@@ -142,14 +142,14 @@ White_space
 
 Showcase
 ```rust
-fn test_i32(b: i32) -> i32 {
+fn test_i32(b: i32, c: i32) -> i32 {
     let a : i32 = 10 + 2 * 3;
     a = -1 - (1 - 1);
     return a + b;
 }
 fn test_bool(b: bool) -> bool {
     if b && true || false {
-        let a : i32 = test_i32(1);
+        let a : i32 = test_i32(1, 999);
         while (a < 5) {
             a = a + 1;
         }
@@ -185,6 +185,35 @@ For furture development
 
 - Compare your solution to the requirements (as stated in the README.md). What are your contributions to the implementation.
 
+Structural Operational Semantics (SOS)
+Symbolx: 
+- σ, state
+- σ', derived state
+- ⇓, evaluates
+- c, command
+- x, variable
+- e, expression
+- b, boolean expression
+
+Command sequence
+
+$\frac{<c1,σ> ⇓ σ' <c2,σ'> ⇓ σ''}{<c1;c2,σ> ⇓ σ''}$
+
+Arithmetic
+
+$\frac{<e1,σ> ⇓ n1 <e2, σ> ⇓ n2}{<e1 + e2, σ> ⇓ n1 plus n2}$
+
+If true
+
+$\frac{<b, σ> ⇓ true <c1, σ> ⇓ σ'}{<if b then c1> ⇓ σ}$
+
+If false
+
+$\frac{<b, σ> ⇓ false <c1, σ> ⇓ σ'}{<if b then c1> ⇓ σ}$
+
+
+
+
 ## Your type checker
 
 - Give an as complete as possible set of Type Checking Rules for your language (those rules look very much like the SOS rules, but over types not values).