ct operator not supported

//Remove PVJ Boat recipes
var boats = [
    <pvj:jacaranda_boat>,
    <pvj:cherry_blossom_boat>,
    <pvj:juniper_boat>,
    <pvj:cottonwood_boat>,
    <pvj:baobab_boat>,
    <pvj:maple_boat>,
    <pvj:aspen_boat>,
    <pvj:pine_boat>,
    <pvj:fir_boat>,
    <pvj:redwood_boat>,
    <pvj:palm_boat>,
    <pvj:willow_boat>,
    <pvj:mangrove_boat>
] as IItemStack[];

var plank = [
    <pvj:planks_jacaranda>,
    <pvj:planks_cherry_blossom>,
    <pvj:planks_juniper>,
    <pvj:planks_cottonwood>,
    <pvj:planks_baobab>,
    <pvj:planks_maple>,
    <pvj:planks_aspen>,
    <pvj:planks_pine>,
    <pvj:planks_fir>,
    <pvj:planks_redwood>,
    <pvj:planks_palm>,
    <pvj:planks_willow>,
    <pvj:planks_mangrove>
] as IItemStack[];

for boat in boats {
    recipes.remove(boat);
}

for i, boat in boats {
    recipes.addShaped(boat[i], [[plank[i], null, plank[i]],[<pyrotech:planks_tarred>, <pyrotech:material:23>, <pyrotech:planks_tarred>]]); ///<-- this is the line that says "operator not supported"
}