diff --git a/dcalc/DmpDelayCalc.cc b/dcalc/DmpDelayCalc.cc
index 4d5d4b14..973b20d3 100644
--- a/dcalc/DmpDelayCalc.cc
+++ b/dcalc/DmpDelayCalc.cc
@@ -24,6 +24,7 @@
 #include "DcalcAnalysisPt.hh"
 #include "GraphDelayCalc.hh"
 #include "DmpCeff.hh"
+#include "Network.hh"
 
 namespace sta {
 
@@ -302,7 +303,7 @@ DmpCeffTwoPoleDelayCalc::loadDelay(const Pin *load_pin,
 				   ArcDelay &wire_delay,
 				   Slew &load_slew)
 {
-  // NEED to handle PiElmore parasitic.
+  // Should handle PiElmore parasitic.
   ArcDelay wire_delay1 = 0.0;
   Slew load_slew1 = drvr_slew_;
   Parasitic *pole_residue = 0;
diff --git a/dcalc/LumpedCapDelayCalc.hh b/dcalc/LumpedCapDelayCalc.hh
index 0f502e33..ff92dea4 100644
--- a/dcalc/LumpedCapDelayCalc.hh
+++ b/dcalc/LumpedCapDelayCalc.hh
@@ -47,7 +47,7 @@ public:
                  // Return values.
                  ArcDelay &gate_delay,
                  Slew &drvr_slew) override;
-  void setMultiDrvrSlewFactor(float) override;
+  void setMultiDrvrSlewFactor(float factor) override;
   float ceff(const LibertyCell *drvr_cell,
              const TimingArc *arc,
              const Slew &in_slew,
diff --git a/dcalc/RCDelayCalc.cc b/dcalc/RCDelayCalc.cc
index 3aec6224..5f852e14 100644
--- a/dcalc/RCDelayCalc.cc
+++ b/dcalc/RCDelayCalc.cc
@@ -62,16 +62,10 @@ RCDelayCalc::dspfWireDelaySlew(const Pin *,
 			       ArcDelay &wire_delay,
 			       Slew &load_slew)
 {
-  float vth = .5;
-  float vl = .2;
-  float vh = .8;
-  float slew_derate = 1.0;
-  if (drvr_library_) {
-    vth = drvr_library_->inputThreshold(drvr_rf_);
-    vl = drvr_library_->slewLowerThreshold(drvr_rf_);
-    vh = drvr_library_->slewUpperThreshold(drvr_rf_);
-    slew_derate = drvr_library_->slewDerateFromLibrary();
-  }
+  float vth = drvr_library_->inputThreshold(drvr_rf_);
+  float vl = drvr_library_->slewLowerThreshold(drvr_rf_);
+  float vh = drvr_library_->slewUpperThreshold(drvr_rf_);
+  float slew_derate = drvr_library_->slewDerateFromLibrary();
   wire_delay = static_cast<float>(-elmore * log(1.0 - vth));
   load_slew = (drvr_slew_ + elmore * log((1.0 - vl) / (1.0 - vh))
 	       / slew_derate) * multi_drvr_slew_factor_;
diff --git a/include/sta/ArcDelayCalc.hh b/include/sta/ArcDelayCalc.hh
index 7eb117ef..045557bb 100644
--- a/include/sta/ArcDelayCalc.hh
+++ b/include/sta/ArcDelayCalc.hh
@@ -40,6 +40,7 @@ class DcalcAnalysisPt;
 //     DmpCeffDelayCalc
 //      DmpCeffElmoreDelayCalc
 //      DmpCeffTwoPoleDelayCalc
+//     ArnoldiDelayCalc
 
 // Abstract class to interface to a delay calculator primitive.
 class ArcDelayCalc : public StaState
diff --git a/liberty/TableModel.cc b/liberty/TableModel.cc
index 605f9086..57c8c446 100644
--- a/liberty/TableModel.cc
+++ b/liberty/TableModel.cc
@@ -1717,13 +1717,11 @@ OutputWaveforms::voltageTimes(size_t wave_index,
     float prev_current = currents->value(0);
     float voltage = 0.0;
     volts.push_back(voltage);
-    bool always_rise = true;
-    bool invert = (always_rise && rf_ == RiseFall::fall());
     for (size_t i = 1; i < time_axis->size(); i++) {
       float time = time_axis->axisValue(i);
       float current = currents->value(i);
       float dv = (current + prev_current) / 2.0 * (time - prev_time) / cap;
-      voltage += invert ? -dv : dv;
+      voltage += dv;
       volts.push_back(voltage);
       prev_time = time;
       prev_current = current;