stop this nonsense

code/modules/research/machinery/_production.dm

@@ -107,7 +107,7 @@
 
 /obj/machinery/rnd/production/proc/check_mat(datum/design/being_built, var/mat)	// now returns how many times the item can be built with the material
 	if (!materials.mat_container)  // no connected silo
-		return 0
+		return FALSE
 	var/list/all_materials = being_built.reagents_list + being_built.materials
 
 	var/A = materials.mat_container.get_material_amount(mat)
@@ -344,10 +344,10 @@
 	var/datum/component/material_container/mat_container = materials.mat_container
 	if (!mat_container)
 		say("No access to material storage, please contact the quartermaster.")
-		return 0
+		return FALSE
 	if (materials.on_hold())
 		say("Mineral access is on hold, please contact the quartermaster.")
-		return 0
+		return FALSE
 	var/count = mat_container.retrieve_sheets(text2num(eject_amt), eject_sheet, drop_location())
 	var/list/matlist = list()
 	matlist[eject_sheet] = MINERAL_MATERIAL_AMOUNT

code/modules/research/xenobiology/crossbreeding/_weapons.dm

@@ -24,7 +24,7 @@
 /obj/item/gun/magic/bloodchill/process()
 	charge_tick++
 	if(charge_tick < recharge_rate || charges >= max_charges)
-		return 0
+		return FALSE
 	charge_tick = 0
 	var/mob/living/M = loc
 	if(istype(M) && M.blood_volume >= 5)
@@ -32,7 +32,7 @@
 		M.blood_volume -= 5
 	if(charges == 1)
 		recharge_newshot()
-	return 1
+	return TRUE
 
 /obj/item/ammo_casing/magic/bloodchill
 	projectile_type = /obj/item/projectile/magic/bloodchill

code/modules/research/xenobiology/xenobiology.dm

@@ -47,7 +47,7 @@
 //Effect when activated by a Luminescent. Separated into a minor and major effect. Returns cooldown in deciseconds.
 /obj/item/slime_extract/proc/activate(mob/living/carbon/human/user, datum/species/jelly/luminescent/species, activation_type)
 	to_chat(user, "<span class='notice'>Nothing happened... This slime extract cannot be activated this way.</span>")
-	return 0
+	return FALSE
 
 //Core-crossing: Feeding adult slimes extracts to obtain a much more powerful, single extract.
 /obj/item/slime_extract/attack(mob/living/simple_animal/slime/M, mob/user)
@@ -97,7 +97,7 @@
 				to_chat(user, "<span class='notice'>You spit out [S].</span>")
 				return 350
 			else
-				return 0
+				return FALSE
 
 /obj/item/slime_extract/gold
 	name = "gold slime extract"