Add use-cases

Co-authored-by: Ezequiel Bellver <ebellver@itba.edu.ar>
Co-authored-by: Juan Barmasch <jbarmasch@itba.edu.ar>

doc/examples/use-case-1.txt

@@ -0,0 +1,11 @@
+function f = x^2;
+function g = { x - 2: x < 3, 
+                     x^3: x >= 5
+                   };
+fun h = x/(x-2);
+
+evaluate f in 3; // 9
+g(5); // 125
+evaluate g in 4; // Error
+g(2); // 0
+h(2); // Error

doc/examples/use-case-10.txt

@@ -0,0 +1,2 @@
+fun f = 1/x;
+fun g =  f(3) + f'(3)*(x-3) + f''(3)/2 * (x-3)^2 + f'''(3) / 6 * (x-3)^3 + f''''(3) / 24 * (x-3)^4;

doc/examples/use-case-13.txt

@@ -0,0 +1,3 @@
+if ("Hola" + g == 2) {
+	print("Funciona");
+}

doc/examples/use-case-15.txt

@@ -0,0 +1,6 @@
+if  (f(0) == 1) {
+	if (g(2) == 4) { 
+		print("Hola");
+	}
+	}
+}

doc/examples/use-case-2.txt

@@ -0,0 +1,3 @@
+eval f in 5;
+
+int f 3 ~ 5;