マインクラフト1.21.8でPvPサーバーを作成中でその際のスクリプトのエラー

var a = "a"
var b = "b"
println("${a}-${b}")

var a = "a"
var b = "b"
println("${a}-${b}")

  if {_job} is "tracker":
    give diamond sword named "&a追跡者の剣" with lore "追跡者の武器" to {_p}
    enchant item in {_p}'s tool with sharpness 4
    enchant item in {_p}'s tool with unbreaking 3

    give shield named "&a追跡者の盾" to {_p}
    enchant item in {_p}'s off hand tool with unbreaking 3

  if {_job} is "tracker":
    give diamond sword named "&a追跡者の剣" with lore "追跡者の武器" to {_p}
    enchant item in {_p}'s tool with sharpness 4
    enchant item in {_p}'s tool with unbreaking 3

    give shield named "&a追跡者の盾" to {_p}
    enchant item in {_p}'s off hand tool with unbreaking 3

if {_job} is not set:
  set {_job} to ""
if {_job} is "":
  # jobがない場合の処理
else:
  # jobがある場合の処理

if {_job} is not set:
  set {_job} to ""
if {_job} is "":
  # jobがない場合の処理
else:
  # jobがある場合の処理

function or(b1: boolean, b2: boolean) :: boolean:
  if {_b1} is true:
    return true
  if {_b2} is true:
    return true
  return false

function or(b1: boolean, b2: boolean) :: boolean:
  if {_b1} is true:
    return true
  if {_b2} is true:
    return true
  return false

if or(check [{_job} is not set], check [{_job} is ""]) is true:

if or(check [{_job} is not set], check [{_job} is ""]) is true:

function endMatch(match_id: string, winner: player, loser: player):
  send title "&a%{winner}% が勝利！" to all players in {_match.%{match_id}%.players::*}
  teleport {_match.%{match_id}%.players::*} to location {@lobby_spawn}
  # アイテムクリア＆コンパス配布処理はlobby_control.sk側で行う
  set {_in_duel.%{winner}%} to false
  set {_in_duel.%{loser}%} to false
  set {_player_lives.%{winner}%} to {@max_lives}
  set {_player_lives.%{loser}%} to {@max_lives}
  delete {_match.%{match_id}%}

function endMatch(match_id: string, winner: player, loser: player):
  send title "&a%{winner}% が勝利！" to all players in {_match.%{match_id}%.players::*}
  teleport {_match.%{match_id}%.players::*} to location {@lobby_spawn}
  # アイテムクリア＆コンパス配布処理はlobby_control.sk側で行う
  set {_in_duel.%{winner}%} to false
  set {_in_duel.%{loser}%} to false
  set {_player_lives.%{winner}%} to {@max_lives}
  set {_player_lives.%{loser}%} to {@max_lives}
  delete {_match.%{match_id}%}