diff --git a/src/debug/WARDuino.ts b/src/debug/WARDuino.ts
index 1984683..fd1f89f 100644
--- a/src/debug/WARDuino.ts
+++ b/src/debug/WARDuino.ts
@@ -5,6 +5,7 @@ export namespace WARDuino {
     import Frame = WASM.Frame;
     import Table = WASM.Table;
     import Memory = WASM.Memory;
+    import Type = WASM.Type;
 
     export interface CallbackMapping {
         callbackid: string;
@@ -77,9 +78,9 @@ export namespace WARDuino {
         pc_error?: number;
         exception_msg?: string;
         breakpoints?: number[];
-        stack?: Value<bigint | number>[];
+        stack?: Value<Type>[];
         callstack?: Frame[];
-        globals?: Value<bigint | number>[];
+        globals?: Value<Type>[];
         table?: Table;
         memory?: Memory;
         br_table?: BRTable;
diff --git a/src/framework/Testee.ts b/src/framework/Testee.ts
index e439e5c..d7a2c5a 100644
--- a/src/framework/Testee.ts
+++ b/src/framework/Testee.ts
@@ -27,7 +27,7 @@ export function timeout<T>(label: string, time: number, promise: Promise<T>): Pr
  * @param field dot string describing the field of the value (or path)
  */
 export function getValue(object: any, field: string): any {
-    if (object?.type == WASM.Type.nothing) {
+    if (object?.type === WASM.Special.nothing) {
         return undefined;
     }
 
diff --git a/src/framework/scenario/Invoker.ts b/src/framework/scenario/Invoker.ts
index 14964ba..d04f373 100644
--- a/src/framework/scenario/Invoker.ts
+++ b/src/framework/scenario/Invoker.ts
@@ -5,6 +5,8 @@ import {Target} from '../Testee';
 import Value = WASM.Value;
 import Type = WASM.Type;
 import nothing = WASM.nothing;
+import Special = WASM.Special;
+import Float = WASM.Float;
 
 export class Invoker implements Step {
     readonly title: string;
@@ -28,9 +30,10 @@ export function invoke(func: string, args: Value<any>[]): Instruction {
     return {kind: Kind.Request, value: Message.invoke(func, args)};
 }
 
-export function returns<T extends bigint | number>(n: Value<T>): Expectation[] {
-    if (n.type == Type.nothing) {
+export function returns<T extends Type>(n: Value<T>): Expectation[] {
+    if (n.type == Special.nothing) {
         return [{'value': {kind: 'primitive', value: undefined} as Expected<undefined>}]
     }
-    return [{'value': {kind: 'primitive', value: n.value} as Expected<T>}]
+    type R = T extends Float ? number : bigint;
+    return [{'value': {kind: 'primitive', value: n.value} as Expected<R>}]
 }
diff --git a/src/messaging/Message.ts b/src/messaging/Message.ts
index e156078..4e72f8a 100644
--- a/src/messaging/Message.ts
+++ b/src/messaging/Message.ts
@@ -28,6 +28,8 @@ export interface Request<R> {
 
 export namespace Message {
     import Inspect = WARDuino.Inspect;
+    import Integer = WASM.Integer;
+    import Float = WASM.Float;
     export const run: Request<Ack> = {
         type: Interrupt.run,
         parser: (line: string) => {
@@ -162,7 +164,7 @@ export namespace Message {
         }
     }
 
-    export function invoke(func: string, args: Value<bigint | number>[]): Request<WASM.Value<bigint | number> | Exception> {
+    export function invoke(func: string, args: Value<Type>[]): Request<WASM.Value<Type> | Exception> {
         function fidx(map: SourceMap.Mapping, func: string): number {
             const fidx: number | void = map.functions.find((closure: SourceMap.Closure) => closure.name === func)?.index;
             if (fidx === undefined) {
@@ -171,15 +173,15 @@ export namespace Message {
             return fidx!;
         }
 
-        function convert(args: Value<bigint | number>[]) {
+        function convert(args: Value<Type>[]) {
             let payload: string = '';
-            args.forEach((arg: Value<bigint | number>) => {
-                if (arg.type === Type.i32 || arg.type === Type.i64) {
-                    payload += WASM.leb128(arg.value);
-                } else {
-                    const buff = Buffer.alloc(arg.type === Type.f32 ? 4 : 8);
-                    write(buff, Number(arg.value), 0, true, arg.type === Type.f32 ? 23 : 52, buff.length);  // todo fix precision loss
+            args.forEach((arg: Value<Type>) => {
+                if (arg.type === Float.f32 || arg.type === Float.f64) {
+                    const buff = Buffer.alloc(arg.type === Float.f32 ? 4 : 8);
+                    write(buff, Number(arg.value), 0, true, arg.type === Float.f32 ? 23 : 52, buff.length);  // todo fix precision loss
                     payload += buff.toString('hex');
+                } else {
+                    payload += WASM.leb128(arg.value);
                 }
             });
             return payload;
diff --git a/src/messaging/Parsers.ts b/src/messaging/Parsers.ts
index d9f6f35..4babeff 100644
--- a/src/messaging/Parsers.ts
+++ b/src/messaging/Parsers.ts
@@ -6,7 +6,7 @@ import {WARDuino} from '../debug/WARDuino';
 import {JSONParse} from 'json-with-bigint';
 import State = WARDuino.State;
 import nothing = WASM.nothing;
-
+import Type = WASM.Type;
 export function identityParser(text: string) {
     return stripEnd(text);
 }
@@ -15,7 +15,7 @@ export function stateParser(text: string): State {
     return JSONParse(text);
 }
 
-export function invokeParser(text: string): WASM.Value<bigint | number> | Exception {
+export function invokeParser(text: string): WASM.Value<Type> | Exception {
     if (exception(text)) {
         return {text: text};
     }
@@ -60,38 +60,50 @@ export function breakpointHitParser(text: string): Breakpoint {
 }
 
 export function signed(value: bigint, bits = 32) {
-    let x = BigInt(value);
+    let x = value;
     const sign = 1n << BigInt(bits - 1);
     const mod = 1n << BigInt(bits);
     return x >= sign ? x - mod : x;
 
 }
 
-function stacking(objects: {value: bigint, type: any}[]): WASM.Value<bigint | number>[] {
-    const stacked: WASM.Value<bigint | number>[] = [];
+function extractType(object: {value: bigint | number, type: any}): Type {
+    if (isNaN(<number>object.value)) return WASM.Special.nan;
+    if (<number>object.value === Infinity) return WASM.Special.infinity;
+    return WASM.typing.get(object.type.toLowerCase()) ?? WASM.Special.unknown;
+}
+
+function stacking(objects: {value: bigint | number, type: any}[]): WASM.Value<Type>[] {
+    const stacked: WASM.Value<Type>[] = [];
     for (const object of objects) {
-        const type: WASM.Type = WASM.typing.get(object.type.toLowerCase()) ?? WASM.Type.unknown;
+        const type: WASM.Type = extractType(object);
         let buff;
         switch (type) {
-            case WASM.Type.u32:
-            case WASM.Type.u64:
+            case WASM.Special.nan:
+                stacked.push({value: NaN, type: type});
+                break;
+            case WASM.Special.infinity:
+                stacked.push({value: Infinity, type: type});
+                break;
+            case WASM.Integer.u32:
+            case WASM.Integer.u64:
                 stacked.push({value: object.value, type: type});
                 break;
-            case WASM.Type.i32:
-                stacked.push({value: signed(object.value, 32), type: type});
+            case WASM.Integer.i32:
+                stacked.push({value: signed(BigInt(object.value), 32), type: type});
                 break;
-            case WASM.Type.i64:
-                stacked.push({value: signed(object.value, 64), type: type});
+            case WASM.Integer.i64:
+                stacked.push({value: signed(BigInt(object.value), 64), type: type});
                 break;
-            case WASM.Type.f32:
+            case WASM.Float.f32:
                 buff = Buffer.from(Number(object.value.toString(16)).toString(16), 'hex');
                 stacked.push({value: ieee754.read(buff, 0, false, 23, buff.length), type: type});
                 break;
-            case WASM.Type.f64:
+            case WASM.Float.f64:
                 buff = Buffer.from(BigInt(object.value.toString(16)).toString(16), 'hex');
                 stacked.push({value: ieee754.read(buff, 0, false, 52, buff.length), type: type});
                 break;
-            case WASM.Type.unknown:
+            case WASM.Special.unknown:
                 break;
         }
     }
diff --git a/src/sourcemap/Wasm.ts b/src/sourcemap/Wasm.ts
index a2d31af..46a3a40 100644
--- a/src/sourcemap/Wasm.ts
+++ b/src/sourcemap/Wasm.ts
@@ -1,57 +1,82 @@
 export namespace WASM {
-    export enum Type {
-        f32,
-        f64,
-        u32,
-        i32,
-        u64,
-        i64,
-        nothing,
-        unknown
+    export enum Float {
+        f32 = 'f32',
+        f64 = 'f64'
     }
 
+    export enum Integer {
+        u32 = 'u32',
+        i32 = 'i32',
+        u64 = 'u64',
+        i64 = 'i64'
+    }
+
+    export enum Special {
+        nothing = 'nothing',
+        nan = 'nan',
+        infinity = 'infinity',
+        unknown = 'unknown'
+    }
+
+    export type Type = Float | Integer | Special;
+
     export const typing = new Map<string, Type>([
-        ['f32', Type.f32],
-        ['f64', Type.f64],
-        ['u32', Type.u32],
-        ['i32', Type.i32],
-        ['u64', Type.u64],
-        ['i64', Type.i64]
+        ['f32', Float.f32],
+        ['f64', Float.f64],
+        ['u32', Integer.u32],
+        ['i32', Integer.i32],
+        ['u64', Integer.u64],
+        ['i64', Integer.i64]
     ]);
 
-    export interface Value<T extends bigint | number>   {
-        type: Type;
-        value: T;
+    export interface Value<T extends Type>   {
+        type: T;
+        value: T extends Integer ? bigint : number;
+    }
+
+    export function equals<T extends Type>(a: Value<T>, b: Value<T>): boolean {
+        switch (a.type) {
+            case Special.nan:
+                return b.type === Special.nan;
+            case Special.infinity:
+                return b.type === Special.infinity;
+            case Special.nothing:
+                return b.type === Special.nothing;
+            case Special.unknown:
+                return b.type === Special.unknown;
+            default:
+                return a.type === b.type && a.value === b.value;
+        }
     }
 
-    export interface Nothing extends Value<number> {}
+    export interface Nothing extends Value<Special> {}
 
     export const nothing: Nothing = {
-        type: Type.nothing, value: 0
+        type: Special.nothing, value: 0
     }
 
-    export function u32(n: bigint): WASM.Value<bigint> {
-        return {value: n, type: Type.u32};
+    export function u32(n: bigint): WASM.Value<Integer> {
+        return {value: n, type: Integer.u32};
     }
 
-    export function i32(n: bigint): WASM.Value<bigint> {
-        return {value: n, type: Type.i32};
+    export function i32(n: bigint): WASM.Value<Integer> {
+        return {value: n, type: Integer.i32};
     }
 
-    export function f32(n: number): WASM.Value<number> {
-        return {value: n, type: Type.f32};
+    export function f32(n: number): WASM.Value<Float> {
+        return {value: n, type: Float.f32};
     }
 
-    export function f64(n: number): WASM.Value<number> {
-        return {value: n, type: Type.f64};
+    export function f64(n: number): WASM.Value<Float> {
+        return {value: n, type: Float.f64};
     }
 
-    export function u64(n: bigint): WASM.Value<bigint> {
-        return {value: n, type: Type.u64};
+    export function u64(n: bigint): WASM.Value<Integer> {
+        return {value: n, type: Integer.u64};
     }
 
-    export function i64(n: bigint): WASM.Value<bigint> {
-        return {value: n, type: Type.i64};
+    export function i64(n: bigint): WASM.Value<Integer> {
+        return {value: n, type: Integer.i64};
     }
 
     export interface Frame {