diff --git a/src/codegen/compiler.rs b/src/codegen/compiler.rs
index c114163..346f81b 100644
--- a/src/codegen/compiler.rs
+++ b/src/codegen/compiler.rs
@@ -751,7 +751,7 @@ mod tests {
 
     tensor_test!{
         exp_function: "r { exp(2) }" expect "r" vec![f64::exp(2.0)],
-        pow_function: "r { pow(4, 0.5) }" expect "r" vec![2.0],
+        pow_function: "r { pow(4.3245, 0.5) }" expect "r" vec![f64::powf(4.3245, 0.5)],
         arcsinh_function: "r { arcsinh(0.5) }" expect "r" vec![f64::asinh(0.5)],
         arccosh_function: "r { arccosh(2) }" expect "r" vec![f64::acosh(2.0)],
         tanh_function: "r { tanh(0.5) }" expect "r" vec![f64::tanh(0.5)],
@@ -763,7 +763,8 @@ mod tests {
         sigmoid_function: "r { sigmoid(0.1) }" expect "r" vec![1.0 / (1.0 + f64::exp(-0.1))],
         scalar: "r {2}" expect "r" vec![2.0,],
         constant: "r_i {2, 3}" expect "r" vec![2., 3.],
-        expression: "r_i {2 + 3, 3 * 2}" expect "r" vec![5., 6.],
+        expression: "r_i {2 + 3, 3 * 2, arcsinh(1.2 + 1.0 / max(1.2, 1.0) * 2.0 + tanh(2.0))}" expect "r" vec![5., 6., f64::asinh(1.2 + 1.0 / f64::max(1.2, 1.0) * 2.0 + f64::tanh(2.0))],
+        unary_negate_in_expr: "r_i { 1.0 / (-1.0 + 1.1) }" expect "r" vec![1.0 / (-1.0 + 1.1)],
         derived: "r_i {2, 3} k_i { 2 * r_i }" expect "k" vec![4., 6.],
         concatenate: "r_i {2, 3} k_i { r_i, 2 * r_i }" expect "k" vec![2., 3., 4., 6.],
         ones_matrix_dense: "I_ij { (0:2, 0:2): 1 }" expect "I" vec![1., 1., 1., 1.],
diff --git a/src/parser/ds_parser.rs b/src/parser/ds_parser.rs
index 61a8d66..c72226e 100644
--- a/src/parser/ds_parser.rs
+++ b/src/parser/ds_parser.rs
@@ -86,7 +86,16 @@ fn parse_value<'a, 'b>(pair: Pair<'a, Rule>) -> Ast<'a> {
             } else {
                 None
             };
-            let mut head_term = parse_value(inner.next().unwrap());
+            let mut head_term =  match sign {
+                Some(s) => Ast {
+                    kind: AstKind::Monop(ast::Monop {
+                        op: s,
+                        child: Box::new(parse_value(inner.next().unwrap())),
+                    }),
+                    span,
+                },
+                None => parse_value(inner.next().unwrap())
+            };
             while inner.peek().is_some() {
                 //term_op    = @{ "-"|"+" }
                 let term_op = parse_sign(inner.next().unwrap());
@@ -104,17 +113,7 @@ fn parse_value<'a, 'b>(pair: Pair<'a, Rule>) -> Ast<'a> {
                     span: subspan,
                 };
             }
-            if sign.is_some() {
-                Ast {
-                    kind: AstKind::Monop(ast::Monop {
-                        op: sign.unwrap(),
-                        child: Box::new(head_term),
-                    }),
-                    span,
-                }
-            } else {
-                head_term
-            }
+            head_term
         }
 
         //term       = { factor ~ (factor_op ~ factor)* }