diff --git a/.fermi.go.swp b/.fermi.go.swp
new file mode 100644
index 0000000..c7848d5
Binary files /dev/null and b/.fermi.go.swp differ
diff --git a/fermi.go b/fermi.go
index 7b05951..ca596cf 100644
--- a/fermi.go
+++ b/fermi.go
@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"git.nunosempere.com/NunoSempere/fermi/sample"
+	"git.nunosempere.com/NunoSempere/fermi/pretty"
 	"math"
 	"os"
 	"sort"
@@ -39,33 +40,6 @@ type FilledSamples struct {
 	xs []float64
 }
 
-/* Constants */
-const GENERAL_ERR_MSG = "  Operation | Variable assignment | Special\n" +
-	"    Operation:                             operator operand\n" +
-	"          operator:                        (empty) | * | / | + | -\n" +
-	"          operand:                         scalar | lognormal | beta | variable\n" +
-	"            lognormal:                     low high\n" +
-	"            beta:                          beta alpha beta\n" +
-	"    Variable assignment:                   =: variable_name\n" +
-	"    Clear stack:                           . | c | clear\n" +
-	"    Variable assignment and clear stack:   =. variable_name\n" +
-	"    Other special operations:              help | debug | exit\n" +
-	"  Examples: \n" +
-	"    + 2\n" +
-	"    / 2.5\n" +
-	"    * 1 10 (interpreted as lognormal)\n" +
-	"    + 1 10\n" +
-	"    * beta 1 10\n" +
-	"    1 10 (multiplication taken as default operation)\n" +
-	"      =: x\n" +
-	"    .\n" +
-	"    1 100\n" +
-	"    + x\n" +
-	"    exit\n"
-const NORMAL90CONFIDENCE = 1.6448536269514727
-const INIT_DIST Scalar = Scalar(1)
-const N_SAMPLES = 100_000
-
 /* Dist interface functions */
 // https://go.dev/tour/methods/9
 func (p Scalar) Samples() []float64 {
@@ -93,8 +67,71 @@ func (fs FilledSamples) Samples() []float64 {
 	return fs.xs
 }
 
-// Parse line into Distribution
+/* Constants */
+const GENERAL_ERR_MSG = "  Operation | Variable assignment | Special\n" +
+	"    Operation:                             operator operand\n" +
+	"          operator:                        (empty) | * | / | + | -\n" +
+	"          operand:                         scalar | lognormal | beta | variable\n" +
+	"            lognormal:                     low high\n" +
+	"            beta:                          beta alpha beta\n" +
+	"    Variable assignment:                   =: variable_name\n" +
+	"    Clear stack:                           . | c | clear\n" +
+	"    Variable assignment and clear stack:   =. variable_name\n" +
+	"    Other special operations:              help | debug | exit\n" +
+	"  Examples: \n" +
+	"    + 2\n" +
+	"    / 2.5\n" +
+	"    * 1 10 (interpreted as lognormal)\n" +
+	"    + 1 10\n" +
+	"    * beta 1 10\n" +
+	"    1 10 (multiplication taken as default operation)\n" +
+	"      =: x\n" +
+	"    .\n" +
+	"    1 100\n" +
+	"    + x\n" +
+	"    exit\n"
+const NORMAL90CONFIDENCE = 1.6448536269514727
+const INIT_DIST Scalar = Scalar(1)
+const N_SAMPLES = 100_000
 
+/* Pretty print for distributions */
+// Needs types
+func prettyPrintDist(dist Dist) {
+	switch v := dist.(type) {
+	case Lognormal:
+		fmt.Printf("=> ")
+		pretty.PrettyPrint2Floats(v.low, v.high)
+	case FilledSamples:
+		tmp_xs := make([]float64, N_SAMPLES)
+		copy(tmp_xs, v.xs)
+		sort.Slice(tmp_xs, func(i, j int) bool {
+			return tmp_xs[i] < tmp_xs[j]
+		})
+		low_int := N_SAMPLES / 20
+		low := tmp_xs[low_int]
+		high_int := N_SAMPLES * 19 / 20
+		high := tmp_xs[high_int]
+		fmt.Printf("=> ")
+		pretty.PrettyPrintFloat(low)
+		fmt.Printf(" ")
+		pretty.PrettyPrintFloat(high)
+		fmt.Printf(" (")
+		pretty.PrettyPrintInt(N_SAMPLES)
+		fmt.Printf(" samples)\n")
+	case Beta:
+		fmt.Printf("=> beta ")
+		pretty.PrettyPrint2Floats(v.a, v.b)
+	case Scalar:
+		fmt.Printf("=> scalar ")
+		w := float64(v)
+		pretty.PrettyPrintFloat(w)
+		fmt.Println()
+	default:
+		fmt.Printf("%v", v)
+	}
+}
+
+// Parse line into Distribution
 func parseLineErr(err_msg string) (string, Dist, error) {
 	fmt.Println(GENERAL_ERR_MSG)
 	fmt.Println(err_msg)
@@ -253,8 +290,10 @@ func divideDists(old_dist Dist, new_dist Dist) (Dist, error) {
 		{
 			switch n := new_dist.(type) {
 			case Lognormal:
+				// to do: check division by zero
 				return multiplyLogDists(o, Lognormal{low: 1.0 / n.high, high: 1.0 / n.low}), nil
 			case Scalar:
+				// to do: check division by zero
 				return multiplyLogDists(o, Lognormal{low: 1.0 / float64(n), high: 1.0 / float64(n)}), nil
 			default:
 				return operateDistsAsSamples(old_dist, new_dist, "/")
@@ -266,6 +305,7 @@ func divideDists(old_dist Dist, new_dist Dist) (Dist, error) {
 			case Lognormal:
 				return multiplyLogDists(Lognormal{low: float64(o), high: float64(o)}, Lognormal{low: 1.0 / n.high, high: 1.0 / n.low}), nil
 			case Scalar:
+				// to do: check division by zero
 				return Scalar(float64(o) / float64(n)), nil
 			default:
 				return operateDistsAsSamples(old_dist, new_dist, "/")
@@ -276,92 +316,9 @@ func divideDists(old_dist Dist, new_dist Dist) (Dist, error) {
 	}
 }
 
-/* Pretty print distributions
- */
-func prettyPrintInt(n int) {
-	switch {
-	case math.Abs(float64(n)) >= 1_000_000_000_000:
-		fmt.Printf("%dT", n/1_000_000_000_000)
-	case math.Abs(float64(n)) >= 1_000_000_000:
-		fmt.Printf("%dB", n/1_000_000_000)
-	case math.Abs(float64(n)) >= 1_000_000:
-		fmt.Printf("%dM", n/1_000_000)
-	case math.Abs(float64(n)) >= 1_000:
-		fmt.Printf("%dK", n/1_000)
-	default:
-		fmt.Printf("%df", n)
-	}
-}
-
-func prettyPrintFloat(f float64) {
-	switch {
-	case math.Abs(f) >= 1_000_000_000_000:
-		fmt.Printf("%.1fT", f/1_000_000_000_000)
-	case math.Abs(f) >= 1_000_000_000:
-		fmt.Printf("%.1fB", f/1_000_000_000)
-	case math.Abs(f) >= 1_000_000:
-		fmt.Printf("%.1fM", f/1_000_000)
-	case math.Abs(f) >= 1_000:
-		fmt.Printf("%.1fK", f/1_000)
-
-	case math.Abs(f) <= 0.0001:
-		fmt.Printf("%.5f", f)
-	case math.Abs(f) <= 0.001:
-		fmt.Printf("%.4f", f)
-	case math.Abs(f) <= 0.01:
-		fmt.Printf("%.3f", f)
-	case math.Abs(f) <= 0.1:
-		fmt.Printf("%.2f", f)
-	default:
-		fmt.Printf("%.1f", f)
-	}
-
-}
-func prettyPrint2Floats(low float64, high float64) {
-	prettyPrintFloat(low)
-	fmt.Printf(" ")
-	prettyPrintFloat(high)
-	fmt.Printf("\n")
-}
-
-func prettyPrintDist(dist Dist) {
-	switch v := dist.(type) {
-	case Lognormal:
-		fmt.Printf("=> ")
-		prettyPrint2Floats(v.low, v.high)
-	case FilledSamples:
-		tmp_xs := make([]float64, N_SAMPLES)
-		copy(tmp_xs, v.xs)
-		sort.Slice(tmp_xs, func(i, j int) bool {
-			return tmp_xs[i] < tmp_xs[j]
-		})
-		low_int := N_SAMPLES / 20
-		low := tmp_xs[low_int]
-		high_int := N_SAMPLES * 19 / 20
-		high := tmp_xs[high_int]
-		fmt.Printf("=> ")
-		prettyPrintFloat(low)
-		fmt.Printf(" ")
-		prettyPrintFloat(high)
-		fmt.Printf(" (")
-		prettyPrintInt(N_SAMPLES)
-		fmt.Printf(" samples)\n")
-	case Beta:
-		fmt.Printf("=> beta ")
-		prettyPrint2Floats(v.a, v.b)
-	case Scalar:
-		fmt.Printf("=> scalar ")
-		w := float64(v)
-		prettyPrintFloat(w)
-		fmt.Println()
-	default:
-		fmt.Printf("%v", v)
-	}
-}
-
 /* Combine old dist and new line */
 // We want this as a function to be able to have parenthesis/recusion, possibly functions
-func combineStackAndDist(stack Stack, new_dist Dist, op string) Stack {
+func operateStackWithDist(stack Stack, new_dist Dist, op string) Stack {
 
 	var combined_dist Dist
 	var err error
@@ -403,7 +360,7 @@ func runRepl(stack Stack, reader *bufio.Reader) Stack {
 		/* Parenthesis */
 		case len(words) == 2 && (words[0] == "*" || words[0] == "+" || words[0] == "-" || words[0] == "/") && words[1] == "(":
 			new_stack := runRepl(Stack{old_dist: INIT_DIST, vars: stack.vars}, reader)
-			stack = combineStackAndDist(stack, new_stack.old_dist, words[0])
+			stack = operateStackWithDist(stack, new_stack.old_dist, words[0])
 			prettyPrintDist(stack.old_dist)
 		case len(words) == 1 && words[0] == ")":
 			return stack
@@ -439,7 +396,7 @@ func runRepl(stack Stack, reader *bufio.Reader) Stack {
 			if err != nil {
 				continue replForLoop
 			}
-			stack = combineStackAndDist(stack, new_dist, op)
+			stack = operateStackWithDist(stack, new_dist, op)
 			prettyPrintDist(stack.old_dist)
 		}
 	}
diff --git a/pretty/pretty.go b/pretty/pretty.go
new file mode 100644
index 0000000..371f9b4
--- /dev/null
+++ b/pretty/pretty.go
@@ -0,0 +1,52 @@
+package pretty
+
+import (
+	"fmt"
+	"math"
+)
+
+func PrettyPrintInt(n int) {
+	switch {
+	case math.Abs(float64(n)) >= 1_000_000_000_000:
+		fmt.Printf("%dT", n/1_000_000_000_000)
+	case math.Abs(float64(n)) >= 1_000_000_000:
+		fmt.Printf("%dB", n/1_000_000_000)
+	case math.Abs(float64(n)) >= 1_000_000:
+		fmt.Printf("%dM", n/1_000_000)
+	case math.Abs(float64(n)) >= 1_000:
+		fmt.Printf("%dK", n/1_000)
+	default:
+		fmt.Printf("%df", n)
+	}
+}
+
+func PrettyPrintFloat(f float64) {
+	switch {
+	case math.Abs(f) >= 1_000_000_000_000:
+		fmt.Printf("%.1fT", f/1_000_000_000_000)
+	case math.Abs(f) >= 1_000_000_000:
+		fmt.Printf("%.1fB", f/1_000_000_000)
+	case math.Abs(f) >= 1_000_000:
+		fmt.Printf("%.1fM", f/1_000_000)
+	case math.Abs(f) >= 1_000:
+		fmt.Printf("%.1fK", f/1_000)
+
+	case math.Abs(f) <= 0.0001:
+		fmt.Printf("%.5f", f)
+	case math.Abs(f) <= 0.001:
+		fmt.Printf("%.4f", f)
+	case math.Abs(f) <= 0.01:
+		fmt.Printf("%.3f", f)
+	case math.Abs(f) <= 0.1:
+		fmt.Printf("%.2f", f)
+	default:
+		fmt.Printf("%.1f", f)
+	}
+
+}
+func PrettyPrint2Floats(low float64, high float64) {
+	PrettyPrintFloat(low)
+	fmt.Printf(" ")
+	PrettyPrintFloat(high)
+	fmt.Printf("\n")
+}