diff --git a/src/main.rs b/src/main.rs
index e543e63..35d540b 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,21 +1,27 @@
-#![warn(clippy::all, clippy::pedantic, clippy::nursery, clippy::cargo)]
+// Enable clippy 'hard mode'
+#![warn(clippy::all, clippy::pedantic, clippy::nursery)]
+// Intended behavior (10_f64 as i32)
+#![allow(clippy::cast_possible_truncation)]
+// Cannot be fixed
+#![allow(clippy::multiple_crate_versions)]
+#![allow(clippy::struct_excessive_bools)]
+
+// #![warn(clippy::all, clippy::pedantic, clippy::nursery, clippy::cargo)]
 // #![allow(dead_code, unused_imports)]
 
 mod errors;
+mod math_eval;
 mod shuf;
 mod sort;
 mod uniq;
 use clap::{Parser, Subcommand};
 use errors::KakMessage;
-use shuf::ShufOptions;
-use sort::SortOptions;
 use std::{
     env, fs,
     fs::{File, OpenOptions},
     io::Write,
     str::FromStr,
 };
-use uniq::UniqOptions;
 
 #[derive(Parser, Debug)]
 #[clap(about, version, author)]
@@ -31,9 +37,11 @@ struct Cli {
 
 #[derive(Subcommand, Debug)]
 enum Commands {
-    Sort(SortOptions),
-    Shuf(ShufOptions),
-    Uniq(UniqOptions),
+    Sort(sort::Options),
+    Shuf(shuf::Options),
+    Uniq(uniq::Options),
+    #[clap(visible_aliases = &["bc", "eval"])]
+    MathEval(math_eval::Options),
 }
 
 #[derive(PartialEq, PartialOrd, Ord, Eq, Debug)]
@@ -102,7 +110,7 @@ impl SelectionDesc {
         let sorted_a = self.sort();
         let sorted_b = b.sort();
 
-        sorted_b.left >= sorted_a.left && sorted_b.right <= sorted_b.right
+        sorted_b.left >= sorted_a.left && sorted_b.right <= sorted_a.right
     }
 }
 
@@ -114,7 +122,7 @@ fn main() {
             eprintln!(
                 "{} (Debug info: {})",
                 msg.0,
-                msg.1.as_ref().unwrap_or(&String::default())
+                msg.1.as_ref().map_or("", String::as_str)
             );
             msg
         }
@@ -150,9 +158,10 @@ fn run() -> Result<KakMessage, KakMessage> {
     })?;
 
     match &options.command {
-        Commands::Sort(sort_options) => sort::sort(sort_options),
-        Commands::Shuf(shuf_options) => shuf::shuf(shuf_options),
-        Commands::Uniq(uniq_options) => uniq::uniq(uniq_options),
+        Commands::Sort(o) => sort::sort(o),
+        Commands::Shuf(o) => shuf::shuf(o),
+        Commands::Uniq(o) => uniq::uniq(o),
+        Commands::MathEval(o) => math_eval::math_eval(o),
     }
 }
 
@@ -195,21 +204,38 @@ pub fn get_var(var_name: &str) -> Result<String, KakMessage> {
 #[cfg(test)]
 mod test {
     use super::*;
+    const sd: SelectionDesc = SelectionDesc {
+        left: AnchorPosition { row: 18, col: 9 },
+        right: AnchorPosition { row: 10, col: 1 },
+    };
     #[test]
     fn test_anchor_position() {
-        let sd = SelectionDesc {
-            left: AnchorPosition { row: 18, col: 9 },
-            right: AnchorPosition { row: 10, col: 0 },
-        };
+        // let sd = SelectionDesc {
+        //     left: AnchorPosition { row: 18, col: 9 },
+        //     right: AnchorPosition { row: 10, col: 0 },
+        // };
         // Check parsing
-        assert_eq!(SelectionDesc::from_str("18.9,10.0").unwrap(), sd);
+        assert_eq!(SelectionDesc::from_str("18.9,10.1").unwrap(), sd);
         // Check if multiple parsed ones match
         assert_eq!(
-            SelectionDesc::from_str("18.9,10.0").unwrap(),
-            SelectionDesc::from_str("18.9,10.0").unwrap()
+            SelectionDesc::from_str("18.9,10.1").unwrap(),
+            SelectionDesc::from_str("18.9,10.1").unwrap()
         );
         // Check if sorting works
-        assert_eq!(sd.sort(), SelectionDesc::from_str("10.0,18.9").unwrap());
+        assert_eq!(sd.sort(), SelectionDesc::from_str("10.1,18.9").unwrap());
         assert_eq!(sd.sort(), sd.sort().sort());
     }
+
+    #[test]
+    fn test_contains() {
+        assert_true!(sd.contains(sd));
+        assert_false!(sd.contains(SelectionDesc::from_str("17.9,10.1").unwrap()))
+        assert_false!(sd.contains(SelectionDesc::from_str("18.8,10.1").unwrap()))
+        assert_false!(sd.contains(SelectionDesc::from_str("18.9,11.1").unwrap()))
+        assert_false!(sd.contains(SelectionDesc::from_str("18.9,10.2").unwrap()))
+        assert_true!(sd.contains(SelectionDesc::from_str("19.9,10.1").unwrap()))
+        assert_true!(sd.contains(SelectionDesc::from_str("18.10,10.1").unwrap()))
+        assert_true!(sd.contains(SelectionDesc::from_str("18.9,9.1").unwrap()))
+        assert_true!(sd.contains(SelectionDesc::from_str("18.9,10.0").unwrap()))
+    }
 }
diff --git a/src/math_eval.rs b/src/math_eval.rs
new file mode 100644
index 0000000..7d27602
--- /dev/null
+++ b/src/math_eval.rs
@@ -0,0 +1,44 @@
+use crate::{kak_response, open_command_fifo, KakMessage};
+use evalexpr::{eval, Value};
+use std::io::Write;
+
+#[derive(clap::StructOpt, Debug)]
+pub struct Options;
+pub fn math_eval(_options: &Options) -> Result<KakMessage, KakMessage> {
+    let selections = kak_response("%val{selections}")?;
+
+    let mut f = open_command_fifo()?;
+    write!(f, "reg '\"'")?;
+
+    let mut err = None;
+    let mut err_count: usize = 0;
+
+    for i in selections.iter().map(|s| {
+        // TODO: Do all of these need to be strings?
+        match eval(s) {
+            Ok(Value::Float(f)) => Some(f.to_string()),
+            Ok(Value::Int(f)) => Some(f.to_string()),
+            // TODO: Should this be none?
+            Ok(_) => None,
+            Err(e) => {
+                eprintln!("Error: {:?}", e);
+                if err.is_none() {
+                    err = Some(e);
+                    err_count = err_count.saturating_add(1);
+                }
+                None
+            }
+        }
+    }) {
+        // TODO: String allocation?
+        let new_selection = i.map(|s| s.replace('\'', "''"));
+        // .unwrap_or_else(|| "".to_string());
+        write!(f, " '{}'", new_selection.as_deref().unwrap_or(""))?;
+    }
+    write!(f, " ; exec R;")?;
+
+    Ok(KakMessage(
+        format!("MathEval {} selections", selections.len()),
+        None,
+    ))
+}
diff --git a/src/shuf.rs b/src/shuf.rs
index a121057..181b2f6 100644
--- a/src/shuf.rs
+++ b/src/shuf.rs
@@ -2,8 +2,8 @@ use crate::{kak_response, open_command_fifo, KakMessage};
 use rand::{seq::SliceRandom, thread_rng};
 use std::io::Write;
 #[derive(clap::StructOpt, Debug)]
-pub struct ShufOptions;
-pub fn shuf(_shuf_options: &ShufOptions) -> Result<KakMessage, KakMessage> {
+pub struct Options;
+pub fn shuf(_options: &Options) -> Result<KakMessage, KakMessage> {
     let mut selections = kak_response("%val{selections}")?;
     let mut rng = thread_rng();
 
@@ -12,7 +12,7 @@ pub fn shuf(_shuf_options: &ShufOptions) -> Result<KakMessage, KakMessage> {
     let mut f = open_command_fifo()?;
     write!(f, "reg '\"'")?;
 
-    for i in selections.iter() {
+    for i in &selections {
         let new_selection = i.replace('\'', "''");
         write!(f, " '{}'", new_selection)?;
     }
diff --git a/src/sort.rs b/src/sort.rs
index 82b901a..ebecbb6 100644
--- a/src/sort.rs
+++ b/src/sort.rs
@@ -4,7 +4,7 @@ use regex::Regex;
 use std::{cmp::Ordering, io::Write, str::FromStr};
 
 #[derive(clap::StructOpt, Debug)]
-pub struct SortOptions {
+pub struct Options {
     #[clap(index = 1)]
     regex: Option<Regex>,
     #[clap(short = 's', long)]
@@ -40,7 +40,7 @@ struct SortableSelection<'a> {
 
 /// Gets a Vec of sortable selections with a given list of subselections and descriptions
 fn get_sortable_selections_subselections<'a, 'b, 'tmp, S: AsRef<str> + std::fmt::Debug + 'a>(
-    sort_options: &'b SortOptions,
+    options: &'b Options,
     selections: &'a [S],
     selections_desc: &'tmp [S],
     subselections: &'a [S],
@@ -57,7 +57,7 @@ fn get_sortable_selections_subselections<'a, 'b, 'tmp, S: AsRef<str> + std::fmt:
         .zip(selections_desc.iter())
         .map(|(s, sd)| {
             Ok((
-                to_sortable_selection(s.as_ref(), sort_options),
+                to_sortable_selection(s.as_ref(), options),
                 SelectionDesc::from_str(sd.as_ref())?,
             ))
         })
@@ -80,7 +80,7 @@ fn get_sortable_selections_subselections<'a, 'b, 'tmp, S: AsRef<str> + std::fmt:
     for (s, s_desc) in &mut sortable_selections {
         for i in &subselections {
             if s_desc.contains(&i.1) {
-                s.subselections.push(i.0.clone());
+                s.subselections.push(i.0);
             }
         }
     }
@@ -106,9 +106,9 @@ fn get_sortable_selections_subselections<'a, 'b, 'tmp, S: AsRef<str> + std::fmt:
 
 fn to_sortable_selection<'a, 'b>(
     selection: &'a str,
-    sort_options: &'b SortOptions,
+    options: &'b Options,
 ) -> SortableSelection<'a> {
-    if sort_options.no_skip_whitespace {
+    if options.no_skip_whitespace {
         SortableSelection {
             content: selection,
             content_comparison: selection,
@@ -123,10 +123,10 @@ fn to_sortable_selection<'a, 'b>(
     }
 }
 
-pub fn sort(sort_options: &SortOptions) -> Result<KakMessage, KakMessage> {
-    eprintln!("Got sort options: {:?}", sort_options);
+pub fn sort(options: &Options) -> Result<KakMessage, KakMessage> {
+    eprintln!("Got sort options: {:?}", options);
 
-    let subselections: Option<(Vec<String>, Vec<String>)> = sort_options
+    let subselections: Option<(Vec<String>, Vec<String>)> = options
         .subselections_register
         .map::<Result<(Vec<String>, Vec<String>), KakMessage>, _>(|_c| {
             let subselections = kak_response("%val{selections}")?;
@@ -142,7 +142,7 @@ pub fn sort(sort_options: &SortOptions) -> Result<KakMessage, KakMessage> {
             let selections_desc = kak_response("%val{selections_desc}")?;
 
             get_sortable_selections_subselections(
-                sort_options,
+                options,
                 &selections,
                 &selections_desc,
                 subselections,
@@ -151,13 +151,13 @@ pub fn sort(sort_options: &SortOptions) -> Result<KakMessage, KakMessage> {
         }
         None => selections
             .iter()
-            .map(|s| to_sortable_selection(s, sort_options))
+            .map(|s| to_sortable_selection(s, options))
             .collect(),
     };
 
     zipped.sort_by(|a, b| {
         for (a_subselection, b_subselection) in a.subselections.iter().zip(b.subselections.iter()) {
-            let comparison = if sort_options.lexicographic_sort {
+            let comparison = if options.lexicographic_sort {
                 a_subselection.cmp(b_subselection)
             } else {
                 compare_str(a_subselection, b_subselection)
@@ -168,7 +168,7 @@ pub fn sort(sort_options: &SortOptions) -> Result<KakMessage, KakMessage> {
             }
         }
 
-        if sort_options.lexicographic_sort {
+        if options.lexicographic_sort {
             a.content_comparison.cmp(b.content_comparison)
         } else {
             compare_str(a.content_comparison, b.content_comparison)
@@ -179,7 +179,7 @@ pub fn sort(sort_options: &SortOptions) -> Result<KakMessage, KakMessage> {
 
     write!(f, "reg '\"'")?;
 
-    let iter: Box<dyn Iterator<Item = _>> = if sort_options.reverse {
+    let iter: Box<dyn Iterator<Item = _>> = if options.reverse {
         Box::new(zipped.iter().rev())
     } else {
         Box::new(zipped.iter())
diff --git a/src/uniq.rs b/src/uniq.rs
index b48ff86..32a914a 100644
--- a/src/uniq.rs
+++ b/src/uniq.rs
@@ -4,27 +4,27 @@ use std::{
     io::Write,
 };
 #[derive(clap::StructOpt, Debug)]
-pub struct UniqOptions {
+pub struct Options {
     #[clap(short, long)]
     ignore_case: bool,
     // TODO: Can we invert a boolean? This name is terrible
     #[clap(short = 'S', long)]
     no_skip_whitespace: bool,
 }
-pub fn uniq(uniq_options: &UniqOptions) -> Result<KakMessage, KakMessage> {
+pub fn uniq(options: &Options) -> Result<KakMessage, KakMessage> {
     let selections = kak_response("%val{selections}")?;
 
     let mut f = open_command_fifo()?;
     write!(f, "reg '\"'")?;
 
     for i in selections.iter().scan(HashMap::new(), |state, s| {
-        let key = if uniq_options.no_skip_whitespace {
+        let key = if options.no_skip_whitespace {
             s
         } else {
             s.trim()
         };
 
-        let key = if uniq_options.ignore_case {
+        let key = if options.ignore_case {
             key.to_lowercase()
         } else {
             // TODO: Do I really need to clone this?