diff --git a/src/parser/mod.rs b/src/parser/mod.rs
index 32522d9..dc88d66 100644
--- a/src/parser/mod.rs
+++ b/src/parser/mod.rs
@@ -9,6 +9,7 @@ use crate::{
     },
 };
 use std::io::SeekFrom;
+use sys_call::SysCall;
 use tree_node::*;
 
 quick_error! {
@@ -165,14 +166,7 @@ impl Parser {
         let expr = Some(match current_token.token_type {
             // match unsupported keywords
             TokenType::Keyword(e)
-                if matches_keyword!(
-                    e,
-                    Keyword::Import,
-                    Keyword::Export,
-                    Keyword::Enum,
-                    Keyword::If,
-                    Keyword::Else
-                ) =>
+                if matches_keyword!(e, Keyword::Enum, Keyword::If, Keyword::Else) =>
             {
                 return Err(ParseError::UnsupportedKeyword(current_token.clone()))
             }
@@ -187,6 +181,11 @@ impl Parser {
             // match functions with a `fn` keyword
             TokenType::Keyword(Keyword::Fn) => Expression::FunctionExpression(self.function()?),
 
+            // match syscalls with a `syscall` keyword
+            TokenType::Identifier(ref id) if SysCall::is_syscall(id) => {
+                Expression::SyscallExpression(self.syscall()?)
+            }
+
             // match a variable expression with opening parenthesis
             TokenType::Identifier(_)
                 if self_matches_peek!(self, TokenType::Symbol(Symbol::LParen)) =>
@@ -689,6 +688,10 @@ impl Parser {
             body: self.block()?,
         })
     }
+
+    fn syscall(&mut self) -> Result<SysCall, ParseError> {
+        todo!("Syscalls are not implemented yet.")
+    }
 }
 
 #[cfg(test)]
@@ -704,12 +707,6 @@ mod tests {
 
     #[test]
     fn test_unsupported_keywords() -> Result<()> {
-        let mut parser = parser!("import x;");
-        assert!(parser.parse().is_err());
-
-        let mut parser = parser!("export x;");
-        assert!(parser.parse().is_err());
-
         let mut parser = parser!("enum x;");
         assert!(parser.parse().is_err());
 
diff --git a/src/parser/sys_call.rs b/src/parser/sys_call.rs
index 596139a..cbc3575 100644
--- a/src/parser/sys_call.rs
+++ b/src/parser/sys_call.rs
@@ -1,4 +1,4 @@
-use super::{Literal, LiteralOrVariable};
+use super::LiteralOrVariable;
 
 #[derive(Debug, PartialEq, Eq)]
 pub enum Math {
@@ -68,6 +68,29 @@ pub enum Math {
     Trunc(LiteralOrVariable),
 }
 
+impl std::fmt::Display for Math {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Math::Acos(a) => write!(f, "acos {}", a),
+            Math::Asin(a) => write!(f, "asin {}", a),
+            Math::Atan(a) => write!(f, "atan {}", a),
+            Math::Atan2(a, b) => write!(f, "atan2 {} {}", a, b),
+            Math::Abs(a) => write!(f, "abs {}", a),
+            Math::Ceil(a) => write!(f, "ceil {}", a),
+            Math::Cos(a) => write!(f, "cos {}", a),
+            Math::Floor(a) => write!(f, "floor {}", a),
+            Math::Log(a) => write!(f, "log {}", a),
+            Math::Max(a, b) => write!(f, "max {} {}", a, b),
+            Math::Min(a, b) => write!(f, "min {} {}", a, b),
+            Math::Rand => write!(f, "rand"),
+            Math::Sin(a) => write!(f, "sin {}", a),
+            Math::Sqrt(a) => write!(f, "sqrt {}", a),
+            Math::Tan(a) => write!(f, "tan {}", a),
+            Math::Trunc(a) => write!(f, "trunc {}", a),
+        }
+    }
+}
+
 #[derive(Debug, PartialEq, Eq)]
 pub enum System {
     /// Pauses execution for exactly 1 tick and then resumes.
@@ -78,22 +101,10 @@ pub enum System {
     /// ## In Game
     /// `sleep a(r?|num)`
     Sleep(LiteralOrVariable),
-    /// Represents a function that can be called to load a variable from a device into a register.
-    /// ## In Game
-    /// `l r? d? logicType`
-    LoadVar(Literal, Literal),
     /// Gets the in-game hash for a specific prefab name.
     /// ## In Game
     /// `HASH("prefabName")`
     Hash(LiteralOrVariable),
-    /// Represents a function which will clear the stack for a provided device.
-    /// ## In Game
-    /// `clr d?`
-    StackClear(Literal),
-    /// Represents a function which reads a value from a device at a specific address and stores it in a register.
-    /// ## In Game
-    /// `get r? d? address(r?|num)`
-    Get(Literal, LiteralOrVariable),
     /// Represents a function which loads a device variable into a register.
     /// ## In Game
     /// `l r? d? var`
@@ -109,6 +120,18 @@ pub enum System {
     Store(String, LiteralOrVariable, LiteralOrVariable),
 }
 
+impl std::fmt::Display for System {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            System::Yield => write!(f, "yield"),
+            System::Sleep(a) => write!(f, "sleep {}", a),
+            System::Hash(a) => write!(f, "HASH({})", a),
+            System::Load(a, b) => write!(f, "l {} {}", a, b),
+            System::Store(a, b, c) => write!(f, "s {} {} {}", a, b, c),
+        }
+    }
+}
+
 #[derive(Debug, PartialEq, Eq)]
 /// This represents built in functions that cannot be overwritten, but can be invoked by the user as functions.
 pub enum SysCall {
@@ -116,3 +139,23 @@ pub enum SysCall {
     /// Represents any mathmatical function that can be called.
     Math(Math),
 }
+
+impl std::fmt::Display for SysCall {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            SysCall::System(s) => write!(f, "{}", s),
+            SysCall::Math(m) => write!(f, "{}", m),
+        }
+    }
+}
+
+impl SysCall {
+    pub fn is_syscall(identifier: &str) -> bool {
+        match identifier {
+            "yield" | "sleep" | "HASH" | "loadFromDevice" | "setOnDevice" => true,
+            "acos" | "asin" | "atan" | "atan2" | "abs" | "ceil" | "cos" | "floor" | "log"
+            | "max" | "min" | "rand" | "sin" | "sqrt" | "tan" | "trunc" => true,
+            _ => false,
+        }
+    }
+}
diff --git a/src/parser/tree_node.rs b/src/parser/tree_node.rs
index a1f448d..9786bdf 100644
--- a/src/parser/tree_node.rs
+++ b/src/parser/tree_node.rs
@@ -1,5 +1,7 @@
 use crate::tokenizer::token::Number;
 
+use super::sys_call::SysCall;
+
 #[derive(Debug, Eq, PartialEq)]
 pub enum Literal {
     Number(Number),
@@ -144,6 +146,15 @@ pub enum LiteralOrVariable {
     Variable(String),
 }
 
+impl std::fmt::Display for LiteralOrVariable {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            LiteralOrVariable::Literal(l) => write!(f, "{}", l),
+            LiteralOrVariable::Variable(v) => write!(f, "{}", v),
+        }
+    }
+}
+
 #[derive(Debug, PartialEq, Eq)]
 pub struct DeviceDeclarationExpression {
     /// any variable-like name 
@@ -174,6 +185,7 @@ pub enum Expression {
     ReturnExpression(Box<Expression>),
     Variable(String),
     DeviceDeclarationExpression(DeviceDeclarationExpression),
+    SyscallExpression(SysCall),
 }
 
 impl std::fmt::Display for Expression {
@@ -192,6 +204,7 @@ impl std::fmt::Display for Expression {
             Expression::PriorityExpression(e) => write!(f, "({})", e),
             Expression::ReturnExpression(e) => write!(f, "(return {})", e),
             Expression::DeviceDeclarationExpression(e) => write!(f, "{}", e),
+            Expression::SyscallExpression(e) => write!(f, "{}", e),
         }
     }
 }
diff --git a/src/tokenizer/mod.rs b/src/tokenizer/mod.rs
index a9d3414..ee30eaa 100644
--- a/src/tokenizer/mod.rs
+++ b/src/tokenizer/mod.rs
@@ -8,7 +8,7 @@ use std::{
     io::{BufReader, Cursor, Read, Seek, SeekFrom},
     path::PathBuf,
 };
-use token::{Keyword, Number, Symbol, Token, TokenType};
+use token::{Keyword, Number, Symbol, Temperature, Token, TokenType};
 
 quick_error! {
     #[derive(Debug)]
@@ -274,7 +274,7 @@ impl Tokenizer {
         }
     }
 
-    /// Tokenizes a number literal
+    /// Tokenizes a number literal. Also handles temperatures with a suffix of `c`, `f`, or `k`.
     fn tokenize_number(&mut self, first_char: char) -> Result<Token, TokenizerError> {
         let mut primary = String::with_capacity(16);
         let mut decimal: Option<String> = None;
@@ -315,29 +315,40 @@ impl Tokenizer {
             self.next_char()?;
         }
 
-        if let Some(decimal) = decimal {
+        let number: Number = if let Some(decimal) = decimal {
             let decimal_scale = decimal.len() as u32;
             let number = format!("{}{}", primary, decimal)
                 .parse::<i128>()
                 .map_err(|e| TokenizerError::NumberParseError(e, self.line, self.column))?;
+            Number::Decimal(
+                Decimal::try_from_i128_with_scale(number, decimal_scale)
+                    .map_err(|e| TokenizerError::DecimalParseError(e, line, column))?,
+            )
+        } else {
+            Number::Integer(
+                primary
+                    .parse()
+                    .map_err(|e| TokenizerError::NumberParseError(e, line, column))?,
+            )
+        };
+
+        // check if the next char is a temperature suffix
+        if let Some(next_char) = self.peek_next_char()? {
+            let temperature = match next_char {
+                'c' => Temperature::Celsius(number),
+                'f' => Temperature::Fahrenheit(number),
+                'k' => Temperature::Kelvin(number),
+                _ => return Ok(Token::new(TokenType::Number(number), line, column)),
+            };
+
+            self.next_char()?;
             Ok(Token::new(
-                TokenType::Number(Number::Decimal(
-                    Decimal::try_from_i128_with_scale(number, decimal_scale)
-                        .map_err(|e| TokenizerError::DecimalParseError(e, line, column))?,
-                )),
+                TokenType::Temperature(temperature),
                 line,
                 column,
             ))
         } else {
-            Ok(Token::new(
-                TokenType::Number(Number::Integer(
-                    primary
-                        .parse()
-                        .map_err(|e| TokenizerError::NumberParseError(e, line, column))?,
-                )),
-                line,
-                column,
-            ))
+            Ok(Token::new(TokenType::Number(number), line, column))
         }
     }
 
@@ -404,8 +415,6 @@ impl Tokenizer {
                 "else" if next_ws!() => keyword!(Else),
                 "return" if next_ws!() => keyword!(Return),
                 "enum" if next_ws!() => keyword!(Enum),
-                "import" if next_ws!() => keyword!(Import),
-                "export" if next_ws!() => keyword!(Export),
                 "device" if next_ws!() => keyword!(Device),
 
                 // boolean literals
@@ -622,19 +631,29 @@ mod tests {
     }
 
     #[test]
-    fn test_skip_line() -> Result<()> {
-        let mut tokenizer = Tokenizer::from(String::from(
-            r#"
-This is a skippable line"#,
-        ));
+    fn test_temperature_unit() -> Result<()> {
+        let mut tokenizer = Tokenizer::from(String::from("10c 10f 10k"));
 
-        tokenizer.skip_line()?;
+        let token = tokenizer.next_token()?.unwrap();
 
-        assert_eq!(tokenizer.line, 2);
-        assert_eq!(tokenizer.column, 1);
+        assert_eq!(
+            token.token_type,
+            TokenType::Temperature(Temperature::Celsius(Number::Integer(10)))
+        );
 
-        let next_char = tokenizer.next_char()?;
-        assert_eq!(next_char, Some('T'));
+        let token = tokenizer.next_token()?.unwrap();
+
+        assert_eq!(
+            token.token_type,
+            TokenType::Temperature(Temperature::Fahrenheit(Number::Integer(10)))
+        );
+
+        let token = tokenizer.next_token()?.unwrap();
+
+        assert_eq!(
+            token.token_type,
+            TokenType::Temperature(Temperature::Kelvin(Number::Integer(10)))
+        );
 
         Ok(())
     }
@@ -772,8 +791,7 @@ This is a skippable line"#,
 
     #[test]
     fn test_keyword_parse() -> Result<()> {
-        let mut tokenizer =
-            Tokenizer::from(String::from("let fn if else return enum import export"));
+        let mut tokenizer = Tokenizer::from(String::from("let fn if else return enum"));
 
         let expected_tokens = vec![
             TokenType::Keyword(Keyword::Let),
@@ -782,8 +800,6 @@ This is a skippable line"#,
             TokenType::Keyword(Keyword::Else),
             TokenType::Keyword(Keyword::Return),
             TokenType::Keyword(Keyword::Enum),
-            TokenType::Keyword(Keyword::Import),
-            TokenType::Keyword(Keyword::Export),
         ];
 
         for expected_token in expected_tokens {
diff --git a/src/tokenizer/token.rs b/src/tokenizer/token.rs
index e507186..cfea770 100644
--- a/src/tokenizer/token.rs
+++ b/src/tokenizer/token.rs
@@ -20,6 +20,23 @@ impl Token {
     }
 }
 
+#[derive(Debug, PartialEq, Hash, Eq, Clone)]
+pub enum Temperature {
+    Celsius(Number),
+    Fahrenheit(Number),
+    Kelvin(Number),
+}
+
+impl std::fmt::Display for Temperature {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Temperature::Celsius(n) => write!(f, "{}°C", n),
+            Temperature::Fahrenheit(n) => write!(f, "{}°F", n),
+            Temperature::Kelvin(n) => write!(f, "{}K", n),
+        }
+    }
+}
+
 #[derive(Debug, PartialEq, Hash, Eq, Clone)]
 pub enum TokenType {
     /// Represents a string token
@@ -34,6 +51,7 @@ pub enum TokenType {
     Identifier(String),
     /// Represents a symbol token
     Symbol(Symbol),
+    Temperature(Temperature),
     /// Represents an end of file token
     EOF,
 }
@@ -47,6 +65,7 @@ impl std::fmt::Display for TokenType {
             TokenType::Keyword(k) => write!(f, "{:?}", k),
             TokenType::Identifier(i) => write!(f, "{}", i),
             TokenType::Symbol(s) => write!(f, "{:?}", s),
+            TokenType::Temperature(t) => write!(f, "{}", t),
             TokenType::EOF => write!(f, "EOF"),
         }
     }
@@ -172,8 +191,6 @@ pub enum Keyword {
     Return,
     /// Represents the `enum` keyword
     Enum,
-    /// Represents an import keyword
-    Import,
-    /// Represents an export keyword
-    Export,
+    /// Represents the `loop` keyword
+    Loop,
 }
diff --git a/tests/file.stlg b/tests/file.stlg
index 341aa7a..530a510 100644
--- a/tests/file.stlg
+++ b/tests/file.stlg
@@ -1,5 +1,15 @@
-fn doStuff(i) {
+device airConditioner = "d1";
+device roomTemperatureSensor = "d2";
+
+loop {
+
+    let currentTemperature = loadFromDevice(roomTemperatureSensor, "Temperature");
+
+    if (currentTemperature > 25c) {
+        setOnDevice(airConditioner, "On", true);
+    } else if (currentTemperature <= 20c) {
+        setOnDevice(airConditioner, "On", false);
+    };
 
 };
 
-doStuff(25 * 2);
\ No newline at end of file