diff --git a/src/experimental/stagag.nim b/src/experimental/stagag.nim
index 71bc7f2..5613c75 100644
--- a/src/experimental/stagag.nim
+++ b/src/experimental/stagag.nim
@@ -352,10 +352,10 @@ proc addFf(g: GaugeV, i = 0) =
 
 var ffList = newSeqWith(1+hmasses.len, newSeq[int](0))
 var ffeList = newSeqWith(1+hmasses.len, newSeq[FloatV](0))
-proc addFx(veps: FloatV, p0,g: GaugeV) =
+proc addFx(veps: FloatV; p0,g: GaugeV; i0,i1: int) =
   var p = p0
   if nf == 0: return
-  for i in 0..hmasses.len:
+  for i in i0..i1:
     addFf(g, i)
     pushMom()
     var va: FloatV
@@ -376,7 +376,15 @@ proc addFx(veps: FloatV, p0,g: GaugeV) =
 
 proc addF(veps: FloatV) =
   if nf == 0: return
-  addFx(veps, momvs[^1], gaugevs[^1])
+  addFx(veps, momvs[^1], gaugevs[^1], 0, hmasses.len)
+
+proc addF(veps: FloatV, i: int) =
+  if nf == 0: return
+  addFx(veps, momvs[^1], gaugevs[^1], i, i)
+
+proc addF(veps: FloatV; i0,i1: int) =
+  if nf == 0: return
+  addFx(veps, momvs[^1], gaugevs[^1], i0, i1)
 
 proc addFF(va, vb: FloatV) =
   if nf == 0: return
@@ -387,7 +395,7 @@ proc addFF(va, vb: FloatV) =
   exp(momvs[^1], vbx, momvs[^2])
   pushMom()
   mul(momvs[^1], momvs[^2], gaugevs[^1])
-  addFx(va, p, momvs[^1])
+  addFx(va, p, momvs[^1], 0, hmasses.len)
 
 proc setupMDx =
   pushTemp()
@@ -461,8 +469,8 @@ proc setupMDababa =
 proc setupMDg5f2 =
   if pt0 == 0: pt0 = 0.1
   if pt1 == 0: pt1 = 0.1
-  if pg0 == 0: pg0 = 0.1
-  if pg1 == 0: pg1 = 0.2
+  if pg0 == 0: pg0 = 0.14
+  if pg1 == 0: pg1 = 0.24
   let t0 = vtau * pushParam(pt0)
   let t02 = 2 * t0
   let t1 = vtau * pushParam(pt1)
@@ -487,6 +495,43 @@ proc setupMDg5f2 =
     addG(g0)
   addT(t0)
 
+proc setupMDg5f23 =
+  if pt0 == 0: pt0 = 0.09
+  if pt1 == 0: pt1 = 0.13
+  if pg0 == 0: pg0 = 0.13
+  if pg1 == 0: pg1 = 0.23
+  if pf0 == 0: pf0 = 0.26
+  let t0 = vtau * pushParam(pt0)
+  let t02 = 2 * t0
+  let t1 = vtau * pushParam(pt1)
+  let t2 = 0.5*vtau - t0 - t1
+  let g0 = vtau * pushParam(pg0)
+  let g1 = vtau * pushParam(pg1)
+  let g2 = vtau - 2*( g0 + g1 )
+  let f00 = vtau * pushParam(pf0)
+  let f01 = vtau - 2*f00
+  let f10 = 0.5*vtau
+  let i0 = hmasses.len
+  let i1 = hmasses.len - 1
+  addT(t0)
+  for i in 0..<nsteps:
+    if i!=0: addT(t02)
+    addG(g0)
+    addF(f00, i0)
+    addT(t1)
+    addG(g1)
+    addF(f10, 0, i1)
+    addT(t2)
+    addG(g2)
+    addF(f01, i0)
+    addT(t2)
+    addF(f10, 0, i1)
+    addG(g1)
+    addT(t1)
+    addF(f00, i0)
+    addG(g0)
+  addT(t0)
+
 proc setupMDg10f2 =
   if pt0 == 0: pt0 = 0.075
   if pt1 == 0: pt1 = 0.07
@@ -1751,6 +1796,7 @@ of "abacaba": setupMDabacaba()
 of "ababababa": setupMDababababa()
 of "acabacabaca": setupMDacabacabaca()
 of "g5f2": setupMDg5f2()
+of "g5f23": setupMDg5f23()
 of "g10f2": setupMDg10f2()
 else:
   echo "unknown MD string: ", md