diff --git a/mers/Cargo.toml b/mers/Cargo.toml
index 7d9b65f..a1305ca 100644
--- a/mers/Cargo.toml
+++ b/mers/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "mers"
-version = "0.9.16"
+version = "0.9.17"
 edition = "2021"
 license = "MIT OR Apache-2.0"
 description = "dynamically typed but type-checked programming language"
@@ -15,7 +15,7 @@ default = ["colored-output"]
 colored-output = ["mers_lib/ecolor-term", "mers_lib/pretty-print", "dep:colored"]
 
 [dependencies]
-mers_lib = "0.9.16"
+mers_lib = "0.9.17"
 # mers_lib = { path = "../mers_lib" }
 clap = { version = "4.3.19", features = ["derive"] }
 colored = { version = "2.1.0", optional = true }
diff --git a/mers_lib/Cargo.toml b/mers_lib/Cargo.toml
index 25d821a..cc35bc6 100755
--- a/mers_lib/Cargo.toml
+++ b/mers_lib/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "mers_lib"
-version = "0.9.16"
+version = "0.9.17"
 edition = "2021"
 license = "MIT OR Apache-2.0"
 description = "library to use the mers language in other projects"
diff --git a/mers_lib/src/program/configs/with_iters.rs b/mers_lib/src/program/configs/with_iters.rs
index bb9f657..fbd4e8a 100755
--- a/mers_lib/src/program/configs/with_iters.rs
+++ b/mers_lib/src/program/configs/with_iters.rs
@@ -51,11 +51,14 @@ impl Config {
                         if a.0.len() == 2 {
                             let mut min = None;
                             let mut max = None;
-                            for v in a.0[0].types.iter().chain(a.0[1].types.iter()) {
+                            for v in &a.0[0].types {
                                 let v = v.as_any().downcast_ref::<data::int::IntT>().ok_or_else(|| CheckError::from(format!("expected int as first argument, but got {}", v.with_info(i))))?;
                                 if min.is_none_or(|min| min > v.0) {
                                     min = Some(v.0);
                                 }
+                            }
+                            for v in &a.0[1].types {
+                                let v = v.as_any().downcast_ref::<data::int::IntT>().ok_or_else(|| CheckError::from(format!("expected int as second argument, but got {}", v.with_info(i))))?;
                                 if max.is_none_or(|max| max < v.1) {
                                     max = Some(v.1);
                                 }
@@ -84,11 +87,14 @@ impl Config {
                         if a.0.len() == 2 {
                             let mut min = None;
                             let mut max = None;
-                            for v in a.0[0].types.iter().chain(a.0[1].types.iter()) {
+                            for v in &a.0[0].types {
                                 let v = v.as_any().downcast_ref::<data::int::IntT>().ok_or_else(|| CheckError::from(format!("expected int as first argument, but got {}", v.with_info(i))))?;
                                 if min.is_none_or(|min| min > v.0) {
                                     min = Some(v.0);
                                 }
+                            }
+                            for v in &a.0[1].types {
+                                let v = v.as_any().downcast_ref::<data::int::IntT>().ok_or_else(|| CheckError::from(format!("expected int as second argument, but got {}", v.with_info(i))))?;
                                 if max.is_none_or(|max| max < v.1) {
                                     max = Some(v.1);
                                 }
@@ -97,7 +103,7 @@ impl Config {
                                 if let Some(max) = max.checked_sub(1) {
                                     o.add(Arc::new(RangeT(min, max)));
                                 } else {
-                                    o.add(Arc::new(RangeT(min.saturating_add(1), max)));
+                                    o.add(Arc::new(RangeT(if min == isize::MIN { min + 1 } else { min }, isize::MIN)));
                                 }
                             }
                         } else {