This espresso source files have been patched so that it can be compiled with gcc 4.2.1 distributed with xcode 8 and gcc 5.4.0 on ubuntu 16.04. Below is the readme from the original author where I cloned these source files from.

[email protected]

This distribution is just a reworked version of the c. 1989 Berkeley
espresso source code.  All I've done is cut the number of files down
to just what is required for a modern POSIXy OS and made those files
more ISO-C compliant.  This should make building espresso a little
easier in these more standards compliant times.

See the file COPYING for the original code licence.  All kudos to the
original authors.

- Andrew

See below for an example input and output from espresso.

The pla for minterm List(0, 1, 3, 7, 8, 9, 11, 15) with 4 predicates (p0 ,p1, p2, p3) looks like below. .e indicates the end of input and output.

      -----------------------------
      .i 4
      .o 1
      0000 1
      0001 1
      0010 0
      0011 1
      0100 0
      0101 0
      0110 0
      0111 1
      1000 1
      1001 1
      1010 0
      1011 1
      1100 0
      1101 0
      1110 0
      1111 1
      .e
      ------------------------------

      The output is below, which indicates the simplify terms [[!p1, !p2], [p2, p3]] --> ((!p1 || !p2) && (p2 || p3)) from -00- and --11

      ------------------------------
      .i 4
      .o 1
      .p 2
      -00- 1
      --11 1
      .e
      ------------------------------