Need help with grammar-kit for left recurrsion

I would like some help getting my BNF working to handle left recursion for a plugin I'm writing.  The plugin is for the HashiCorp Sentinel language which is based on a mix of Go and Python.  Here is the language spec: https://docs.hashicorp.com/sentinel/language/spec/

I'm stuck on how to handle left recursion for "PrimaryExpression" and I don't know how to fix it.  I was able to make grammar-kit happy with "Expression".  I think the problem is that not all the child rules completely inherit from the parent but I don't know how to make that happen.  Below a the partial BNF file.

{
  parserClass="com.github.tylersmith34.intellijhashicorpsentinel.SentinelParser"
  parserUtilClass="com.github.tylersmith34.intellijhashicorpsentinel.SentinelParserUtil"

  extends="com.intellij.extapi.psi.ASTWrapperPsiElement"

  psiClassPrefix="Sentinel"
  psiImplClassSuffix="Impl"
  psiPackage="com.github.tylersmith34.intellijhashicorpsentinel.psi"
  psiImplPackage="com.github.tylersmith34.intellijhashicorpsentinel.psi.impl"

  elementTypeHolderClass="com.github.tylersmith34.intellijhashicorpsentinel.SentinelTypes"
  elementTypeClass="com.github.tylersmith34.intellijhashicorpsentinel.psi.SentinelElementType"
  tokenTypeClass="com.github.tylersmith34.intellijhashicorpsentinel.psi.SentinelTokenType"

  psiImplUtilClass="com.github.tylersmith34.intellijhashicorpsentinel.psi.impl.SentinelPsiImplUtil"

    tokens = [
        IDENTIFIER = 'regexp:[a-zA-Z_][a-zA-Z0-9_]*'
        WHITE_SPACE = 'regexp:\s+'
        DOUBLE_QUOTED_STRING="regexp:\"([^\\\"\r\n]|\\[^\r\n])*\"?"
        SINGLE_QUOTED_STRING="regexp:'([^\\\'\r\n]|\\[^\r\n])*'?"
        COMMENT = "regexp:(//.*)|(#.*)"
        BLOCK_COMMENT = "regexp:/\*([^*]|\*[^/])*\*?(\*/)?"
        NUMBERS='regexp:-?(0x)?(0|[1-9])\d*(\.\d+)?([eE][-+]?\d+)?'
        L_BRACKET='['
        R_BRACKET=']'
        L_CURLY='{'
        R_CURLY='}'
        L_PAREN='('
        R_PAREN=')'
        COMMA=','
        PERIOD='.'
        EQUALS='='
        LESS_THAN='<'
        MINUS='-'
        PLUS='+'
        SPLAT='*'
        SLASH='/'
        PERCENT='%'
        COLON=':'
        DOUBLE_EQUALS='=='
        NOT_EQUALS='!='
        LESS_THAN_EQUALS='<='
        GREATER_THAN='>'
        GREATER_THAN_EQUALS='>='
        MINUS='-'
        EXCLAMATION='!'
   ]
}

//SimpleFile ::= IfStatement*
SimpleFile ::= Definition*
Definition ::= { ImportStatement | ExternalParameters | Variable}

//Complex Objects
Object ::= String | Constants
String ::= ('"' ( Letter | EscapedCharacter )* '"') | DOUBLE_QUOTED_STRING | SINGLE_QUOTED_STRING
Variable ::= IDENTIFIER EQUALS ExpressionList


//import
ImportStatement ::= import String (as IDENTIFIER )?

//External param
ExternalParameters       ::= param IDENTIFIER ( default Object )?

//Primitive types
Constants ::= BooleanLiteral | NullLiteral | UndefinedLiteral
BooleanLiteral   ::= true | false
NullLiteral      ::= null
UndefinedLiteral ::= undefined
Letter           ::= "A" | "B" | "C" | "D" | "E" | "F" | "G" | "H" | "I" | "J" | "K" | "L" | "M" | "N" | "O" | "P" | "Q" | "R" | "S" | "T" | "U" | "V" | "W" | "X" | "Y" | "Z" | "a" | "b" | "c" | "d" | "e" | "f" | "g" | "h" | "i" | "j" | "k" | "l" | "m" | "n" | "o" | "p" | "q" | "r" | "s" | "t" | "u" | "v" | "w" | "x" | "y" | "z"
EscapedCharacter ::= '\' ( "a" | "b" | "f" | "n" | "r" | "t" | "v" | '\' | '"' )

ExpressionList ::= Expression ("," Expression )*
Expression ::= Expr
Expr ::= UnaryExpr | ExprWithExpr
ExprWithExpr ::= Expr binary_op Expr {extends=Expr}
UnaryExpr  ::= PrimaryExpression | unary_op UnaryExpr {extends=Expr}
binary_op  ::= logical_op | set_op | rel_op | add_op | mul_op | else_op
logical_op ::= "and" | "or" | "xor"
set_op     ::= ("not")? ( "contains" | "in" )
rel_op     ::= "==" | "!=" | "<" | "<=" | ">" | ">=" | "is" | "is not" | "matches" | "not matches"
add_op     ::= "+" | "-"
mul_op     ::= "*" | "/" | "%"
unary_op   ::= "+" | "-" | "!" | "not"
else_op    ::= else

PrimaryExpression ::=  Operand | PrimarySelectorExpr |    PrimaryIndexExpr | PrimarySliceExpr | PrimaryArgumentsExpr
private PrimaryArgumentsExpr ::= PrimaryExpression Arguments {extends=PrimaryExpression}
private PrimarySliceExpr ::= PrimaryExpression Slice {extends=PrimaryExpression}
private PrimaryIndexExpr ::= PrimaryExpression Index {extends=PrimaryExpression}
private PrimarySelectorExpr ::= PrimaryExpression Selector {extends=PrimaryExpression}

Selector      ::= "." IDENTIFIER {extends=PrimaryExpression}
Index         ::= "[" Expression "]" {extends=PrimaryExpression}
Slice         ::= "[" [ Expression ] ":" [ Expression ] "]" | "[" [ Expression ] ":" Expression ":" Expression "]" {extends=PrimaryExpression}
Arguments     ::= "(" [ ( ExpressionList ) [ "..." ] [ "," ] ] ")" {extends=PrimaryExpression}

Operand     ::= Literal | OperandName | "(" Expression ")" {extends=PrimaryExpression}
Literal     ::= BasicLit
BasicLit    ::= String
OperandName ::= IDENTIFIER