diff --git a/midas/parser/midas.py b/midas/parser/midas.py
index 146ef54..6678dbc 100644
--- a/midas/parser/midas.py
+++ b/midas/parser/midas.py
@@ -632,7 +632,7 @@ class MidasParser(Parser[list[Stmt]]):
             return WildcardExpr(location=token.get_location(), token=token)
 
         if self.match(TokenType.LEFT_PAREN):
-            expr: Expr = self.constraint()
+            expr: Expr = self.expression()
             right: Token = self.consume(TokenType.RIGHT_PAREN, "Unclosed parenthesis")
             return GroupingExpr(location=token.location_to(right), expr=expr)
 
diff --git a/syntax/midas.ebnf b/syntax/midas.ebnf
index 4626412..a2bf9de 100644
--- a/syntax/midas.ebnf
+++ b/syntax/midas.ebnf
@@ -4,40 +4,87 @@ Identifier ::= [a-zA-Z_] [a-zA-Z_0-9]*
 Integer ::= '\d+'
 Number ::= "-"? Integer ("." Integer)?
 Boolean ::= "False" | "True"
+String ::= '(".*?")|(\'.*?\')'
 None ::= "None"
 
-Value ::= Number | Boolean | None
+Literal ::= Number | Boolean | String | None
 
+UnaryOp ::= "+" | "-" | "!"
+FactorOp ::= "*" | "/"
+TermOp ::= "+" | "-"
 ComparisonOp ::= ">" | "<" | ">=" | "<="
 EqualityOp ::= "==" | "!="
 
-Grouping ::= "(" Constraint ")"
-Primary ::= "_" | Value | Identifier | Grouping
+PosArg ::= Expression
+KwArg ::= Identifier "=" Expression
+
+PosArgs ::= PosArg ("," PosArg)*
+KwArgs ::= KwArg ("," KwArg)*
+Args ::= (
+    PosArgs
+    | KwArgs
+    | PosArgs "," KwArgs
+)
+
+Grouping ::= "(" Expression ")"
+Primary ::= "_" | Literal | Identifier | Grouping
 Reference ::= Primary ("." Identifier)*
-Unary ::= "-"? Unary | Reference
-Comparison ::= Unary (ComparisonOp Unary)*
+CallArgs ::= "(" Args ")" 
+Call ::= Reference CallArgs*
+Unary ::= UnaryOp Unary | Call
+Factor ::= Unary (FactorOp Unary)*
+Term ::= Factor (TermOp Factor)*
+Comparison ::= Term (ComparisonOp Term)*
 Equality ::= Comparison (EqualityOp Comparison)*
-Constraint ::= Equality ("&" Equality)*
+Expression ::= Equality ("&" Equality)*
+Constraint ::= Expression
 
 TemplateParam ::= Identifier ("<:" Type)?
 Template ::= "[" (TemplateParam ("," TemplateParam)*)? "]"
 
+ParamType ::= Type "?"?
+PosParam ::= (Identifier ":")? ParamType
+KwParam ::= Identifier ":" ParamType
+
+PosParams ::= (
+    (PosParam ("," PosParam)* ("," "/")?)
+    | "/"
+)
+MixedParams ::= KwParam ("," KwParam)
+KwParams ::= (
+    (("*", ",")? KwParam ("," KwParam)*)
+    | "*"
+)
+Params ::= (
+    PosParams
+    | MixedParams
+    | KwParams
+    | (PosParams "," MixedParams)
+    | (PosParams "," KwParams)
+    | (MixedParams "," KwParams)
+    | (PosParams "," MixedParams "," KwParams)
+)
+ParamSpec ::= "(" Params? ")"
 
 TypeProperty ::= Identifier ":" Type
 ComplexType ::= "{" TypeProperty* "}"
 NamedType ::= Identifier
-TypeParams ::= "[" (Type ("," Type)*)? "]"
-GenericType ::= NamedType TypeParams?
+TypeArgs ::= "[" (Type ("," Type)*)? "]"
+FrameColumn ::= TOKEN ":" Type
+FrameSchema ::= "[" (FrameColumn ("," FrameColumn)*)? "]"
+GenericType ::= "Frame" FrameSchema | NamedType TypeArgs?
 GroupedType ::= "(" Type ")"
 BaseType ::= GroupedType | ComplexType | GenericType
 ConstraintType ::= BaseType ("where" Constraint)?
+FuncType ::= "fn" ParamSpec "->" Type
 Type ::= ConstraintType
 
-OpDefinition ::= "op" Identifier "(" Type ")" "->" Type
-ExtendBody ::= "{" OpDefinition* "}"
+MemberStatement ::= ("prop" | "def") Identifier ":" Type
+ExtendBody ::= "{" MemberStatement* "}"
 
+AliasStatement ::= "alias" Identifier "=" Type
 TypeStatement ::= "type" Identifier Template? "=" Type
 ExtendStatement ::= "extend" Type ExtendBody
-PredicateStatement ::= "predicate" Identifier "(" Identifier ":" Type ")" "=" Constraint
+PredicateStatement ::= "predicate" Identifier ParamSpec* "=" Constraint
 
-Statement ::= TypeStatement | ExtendStatement | PredicateStatement
+Statement ::= AliasStatement | TypeStatement | ExtendStatement | PredicateStatement
diff --git a/syntax/midas.typ b/syntax/midas.typ
index b05c2a5..736d0a3 100644
--- a/syntax/midas.typ
+++ b/syntax/midas.typ
@@ -7,20 +7,21 @@ svg.railroad .terminal rect {
 ```
 #let css = default-css() + bytes(extra-css.text)
 
-#let value = ```
-{[`value` <
+#let literal = ```
+{[`literal` <
   [`number` 'digit' * ! <!, ["." 'digit' * !]>],
   [`boolean` <"False", "True">],
+  [`string` <["\"" 'char'*! "\""], ["'" 'char'*! "'"]>],
   [`none` "None"]
 >]}
 ```
 
 #let grouping = ```
-{[`grouping` "(" 'constraint' ")"]}
+{[`grouping` "(" 'expression' ")"]}
 ```
 
 #let primary = ```
-{[`primary` <"_", 'value', 'identifier', 'grouping'>]}
+{[`primary` <"_", 'literal', 'identifier', 'grouping'>]}
 ```
 
 #let reference = ```
@@ -152,7 +153,7 @@ svg.railroad .terminal rect {
 ```
 
 #let rules = (
-  value: value,
+  literal: literal,
   grouping: grouping,
   primary: primary,
   reference: reference,
@@ -190,7 +191,7 @@ svg.railroad .terminal rect {
 
 #let inline = (
   "grouping",
-  "value",
+  "literal",
   "template-param",
   "template",
   "type-property",