diff --git a/README.md b/README.md
index dbaf8aa..7790198 100644
--- a/README.md
+++ b/README.md
@@ -26,12 +26,12 @@ local function mystart(parsed_code)
 			return true
 		end
 	end, parsed_code)
-	mykeepalive()
+	mykeepalive(thread)
 end
 
 mystart(parsed_code)
 
-local function mykeepalive()
+local function mykeepalive(thread)
 	thread:suscitate()
 	if not thread.stopped then
 		return
diff --git a/faden.lua b/faden.lua
index 4ab0fe8..c9d8c0f 100644
--- a/faden.lua
+++ b/faden.lua
@@ -4,7 +4,7 @@ local function befehl_ausfuhren(faden)
 	local vars = faden.vars
 	local befehl, args = unpack(faden.liste[faden.ip])
 	for i = 1,#is do
-		local bfunk = is[i]
+		local bfunk = is[i][befehl]
 		if bfunk then
 			local fa = {}
 			local ersetzbar = {}
@@ -31,6 +31,10 @@ local function befehl_ausfuhren(faden)
 					if not ersetzbar[i] then
 						return false, "Attempt on changing an immediate"
 					end
+					if not args[i] then
+						-- FIXME
+						error"[pdisc] instruction set attempt to write in void"
+					end
 					vars[args[i]] = v
 				end
 			end
@@ -48,7 +52,7 @@ local function programm_ausfuhren(faden)
 	local weiter,msg = befehl_ausfuhren(faden)
 	if not weiter then
 		faden.log = faden.log .. "Aborted: " .. msg .. "\n"
-		faden.exit()
+		faden:exit()
 		return
 	end
 	return not faden.stopped and programm_ausfuhren(faden)
@@ -57,6 +61,7 @@ end
 return function(faden_manip, parsed)
 	local faden = {
 		log = "",
+		vars = {pi = math.pi},
 		ip = 1,
 		sp = 50,
 		sb = 50,
@@ -76,7 +81,7 @@ return function(faden_manip, parsed)
 			self:suscitate()
 		end,
 		try_rebirth = function(self)
-			if minetest.get_gametime() < self.rebirth then
+			if minetest.get_gametime() >= self.rebirth then
 				self:continue()
 			end
 		end,
diff --git a/parser.lua b/parser.lua
index 7314b50..1789718 100644
--- a/parser.lua
+++ b/parser.lua
@@ -13,7 +13,7 @@ local function parse_zeile(marken, imms, z, zn)
 	-- Marke erkennen
 	local marke = z:find":"
 	if marke then
-		mname = z:sub(1, marke - 1)
+		local mname = z:sub(1, marke - 1)
 		marken[mname] = zn
 
 		z = z:sub(marke+1):trim()
@@ -61,15 +61,20 @@ return function(programm)
 	local marken = {}
 
 	-- Programm erkennen
-	local liste = programm:split"\n"
-	local zn = #liste
-	for i = 1,zn do
-		liste[i] = parse_zeile(marken, imms, liste[i], i)
+	local zeilen = programm:split"\n"
+	local anz = 0
+	local liste = {}
+	for i = 1,#zeilen do
+		local befehl = parse_zeile(marken, imms, zeilen[i], i)
+		if befehl[1] then
+			anz = anz + 1
+			liste[anz] = befehl
+		end
 	end
 	local immn = #imms+1
 
 	-- Marken durch immediates ersetzen
-	for i = 1,zn do
+	for i = 1,anz do
 		local args = liste[i][2]
 		if args then
 			for i = 1,#args do
diff --git a/standardbefehlssatz.lua b/standardbefehlssatz.lua
index 32f26f1..556df2a 100644
--- a/standardbefehlssatz.lua
+++ b/standardbefehlssatz.lua
@@ -25,12 +25,73 @@ s = {
 		if t1 == "number" then
 			return true, p1 + p2
 		end
-		if t1 == "string" then
-			return true, p1 .. p2
+		if t1 == "boolean" then
+			return true, p1 and p2
+		end
+		return true, p1 .. p2
+	end,
+
+	mul = function(params)
+		if #params ~= 2 then
+			return false, WNOA
+		end
+		local p1,p2 = unpack(params)
+		local t1 = type(p1)
+		local t2 = type(p2)
+		if t1 == "string"
+		and t2 == "number" then
+			return true, p1:rep(p2)
+		end
+		if t1 ~= t2 then
+			return false, "different argument types"
+		end
+
+		if t1 == "number" then
+			return true, p1 * p2
+		end
+		if t1 == "boolean" then
+			return true, p1 or p2
 		end
 		return false, UAT
 	end,
 
+	neg = function(params)
+		if #params ~= 1 then
+			return false, WNOA
+		end
+		local v = params[1]
+		local t = type(v)
+		if t == "number" then
+			return true, -v
+		end
+		if t == "boolean" then
+			return true, not v
+		end
+		return true, v:rev()
+	end,
+
+	inv = function(params)
+		if #params ~= 1 then
+			return false, WNOA
+		end
+		local p = params[1]
+		if type(p) ~= "number" then
+			return false, UAT
+		end
+		return true, 1 / p
+	end,
+
+	mod = function(params)
+		if #params ~= 2 then
+			return false, WNOA
+		end
+		local p1,p2 = unpack(params)
+		if type(p1) ~= "number" or type(p2) ~= "number" then
+			return false, UAT
+		end
+		return true, p1 % p2
+	end,
+
 	jmp = function(params, faden)
 		if #params ~= 1 then
 			return false, WNOA
@@ -131,8 +192,39 @@ s = {
 		return true
 	end,
 
+	tostring = function(params)
+		if #params ~= 1 then
+			return false, WNOA
+		end
+		return true, tostring(params[1])
+	end,
+
+	print = function(params, faden)
+		for i = 1,#params do
+			params[i] = tostring(params[i])
+		end
+		faden.log = faden.log .. table.concat(params, "\t") .. "\n"
+		return true
+	end,
+
 	flush = function(params, faden)
 		return faden:flush(params)
 	end,
 }
+
+local so_math_fcts = {"sin", "asin", "cos", "acos", "tan", "atan",
+	"abs", "sign", "floor", "ceil"}
+for i = 1,#so_math_fcts do
+	i = so_math_fcts[i]
+	s[i] = function(params)
+		if #params ~= 1 then
+			return false, WNOA
+		end
+		local p = params[1]
+		if type(p) ~= "number" then
+			return false, UAT
+		end
+		return true, math[i](p)
+	end
+end
 return s