-Hardware description languages (\acrop{HDL}) have allowed the productivity of
-hardware engineers to keep pace with the development of chip technology.
-Traditional \acrop{HDL}, like \VHDL~\cite{VHDL2008} and
-Verilog~\cite{Verilog}, allowed an engineer to describe circuits using a
-`programming' language. These standard languages are very good at describing
-detailed hardware properties such as timing behavior, but are generally
-cumbersome in expressing higher-level abstractions. In an attempt to raise the
-abstraction level of the descriptions, a great number of approaches based on
-functional languages has been proposed \cite{Cardelli1981,muFP,DAISY,
-T-Ruby,HML2,Hydra,Hawk1,Lava,Wired,ForSyDe1,reFLect}. The idea of using
-functional languages for hardware descriptions started in the early 1980s
-\cite{Cardelli1981,muFP,DAISY}, a time which also saw the birth of the
-currently popular \acrop{HDL}, such as \VHDL. Functional
-languages are especially well suited to describe hardware because
-combinational circuits can be directly modeled as mathematical functions and
-functional languages are very good at describing and composing these
-functions.
+Hardware description languages (\acrop{HDL}) have not allowed the productivity
+of hardware engineers to keep pace with the development of chip technology.
+While traditional \acrop{HDL}, like \VHDL~\cite{VHDL2008} and
+Verilog~\cite{Verilog}, are very good at describing detailed hardware
+properties such as timing behavior, they are generally cumbersome in
+expressing the higher-level abstractions needed for today's large and complex
+circuit designs. In an attempt to raise the abstraction level of the
+descriptions, a great number of approaches based on functional languages has
+been proposed \cite{Cardelli1981,muFP,DAISY,T-Ruby,HML2,Hydra,Hawk1,Lava,
+Wired,ForSyDe1,reFLect}. The idea of using functional languages for hardware
+descriptions started in the early 1980s \cite{Cardelli1981,muFP,DAISY}, a
+time which also saw the birth of the currently popular \acrop{HDL}, such as
+\VHDL. Functional languages are especially well suited to describe hardware
+because combinational circuits can be directly modeled as mathematical
+functions and functional languages are very good at describing and composing
+these functions.