diff --git a/Cargo.lock b/Cargo.lock
index 378c4bf..4c0e99a 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -75,6 +75,7 @@ dependencies = [
  "serde-wasm-bindgen",
  "serde_json",
  "wasm-bindgen",
+ "web-sys",
 ]
 
 [[package]]
@@ -477,6 +478,16 @@ dependencies = [
  "unicode-ident",
 ]
 
+[[package]]
+name = "web-sys"
+version = "0.3.82"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3a1f95c0d03a47f4ae1f7a64643a6bb97465d9b740f0fa8f90ea33915c99a9a1"
+dependencies = [
+ "js-sys",
+ "wasm-bindgen",
+]
+
 [[package]]
 name = "windows-sys"
 version = "0.59.0"
diff --git a/Cargo.toml b/Cargo.toml
index 71e8d27..f99620f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -12,4 +12,5 @@ serde = { version = "1.0.228", features = ["derive"] }
 serde-wasm-bindgen = "0.6.5"
 serde_json = "1.0.145"
 wasm-bindgen = "0.2.105"
+web-sys = { version = "0.3.82", features = ["console"] }
 
diff --git a/pkg/argus_wasm.js b/pkg/argus_wasm.js
index d89319b..cd55ab6 100644
--- a/pkg/argus_wasm.js
+++ b/pkg/argus_wasm.js
@@ -352,6 +352,9 @@ function __wbg_get_imports() {
         const ret = arg0.length;
         return ret;
     };
+    imports.wbg.__wbg_log_eeaf399d6effdabf = function(arg0, arg1) {
+        console.log(arg0, arg1);
+    };
     imports.wbg.__wbg_new_1acc0b6eea89d040 = function() {
         const ret = new Object();
         return ret;
diff --git a/pkg/argus_wasm_bg.wasm b/pkg/argus_wasm_bg.wasm
index 87d21e0..3391a87 100644
Binary files a/pkg/argus_wasm_bg.wasm and b/pkg/argus_wasm_bg.wasm differ
diff --git a/src/lib.rs b/src/lib.rs
index 7d7b176..de0e5bd 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -4,6 +4,7 @@ extern crate serde_json;
 extern crate js_sys;
 extern crate serde;
 extern crate serde_wasm_bindgen;
+extern crate web_sys;
 
 use wasm_bindgen::prelude::*;
 
@@ -15,6 +16,7 @@ use std::vec;
 use serde::{Serialize, Deserialize};
 use serde_wasm_bindgen::{from_value, to_value};
 use std::time::Duration;
+use web_sys::console;
 
 struct TraceMap<'a> {
     traces: HashMap<&'a str, Signal<f64>>,
@@ -70,6 +72,10 @@ pub fn eval_boolean(s: &str, js_trace: JsValue) -> JsValue {
             }
         }
     }
+    let m = TraceMap{traces: traceMap};
+    for name in m.signal_names() {
+        console::log_2(&JsValue::from_str("signal name:"), &JsValue::from_str(name));
+    }
     // parse property string
     let parse_result = argus::parse_str(s);
     let expr = match parse_result {
@@ -82,7 +88,7 @@ pub fn eval_boolean(s: &str, js_trace: JsValue) -> JsValue {
     };
     // evaluate property on trace
     let eval_result = match expr {
-        Expr::Bool(bool_expr) => BooleanSemantics::eval::<interpolation::Constant>(&bool_expr, &TraceMap{traces: traceMap}),
+        Expr::Bool(bool_expr) => BooleanSemantics::eval::<interpolation::Constant>(&bool_expr, &m),
         _ => return JsValue::from_str("expected boolean expression (this should never happen)"),
     };
     let mut result = Vec::<StateBuddyEvalResultEntry>::new();