Issue #96: missing file

Author: bcbeckman

examples/symbolic_logic/gries_schneider/GS0.m

@@ -0,0 +1,46 @@
+(* ****************************************************************************
+
+    by Brian Beckman. License the same as for mathics.
+
+    Oct 2020
+
+    These examples are adapted from Gries & Schnedier, "A Logical Approach
+    to Discrete Math." The bibtex entry for this book follows:
+
+    @Book{gries1993a,
+     author = {Gries, David},
+     title = {A Logical Approach to Discrete Math},
+     publisher = {Springer New York},
+     year = {1993},
+     address = {New York, NY},
+     isbn = {978-1-4757-3837-7}}
+
+ *************************************************************************** *)
+
+(* ***************************************************************************
+
+    This file contains tooling so we can write 'expected' and 'actual' in our
+    examples. You don't need to understand how this works. You just need to know
+    how to use it, and you'll see how in the examples in GS1.m, GS2.m, GS3.m.
+
+ *************************************************************************** *)
+
+ClearAll[expect, totalRight, totalWrong, totalTests];
+SetAttributes[ expect, HoldAllComplete ];
+totalRight = totalWrong = totalTests = 0;
+expect[expected_, actual_] := (* <~~~ Here's the API *)
+   Module[{evalActualOnce = actual,
+           evalExpectedOnce = expected},
+      totalTests += 1;
+      Print[ {"Test[" <> ToString[totalTests] <> "]:=\n",
+              HoldForm[actual],
+              "\nexpected", HoldForm[expected],
+              "\neval'd expected", evalExpectedOnce,
+              "\neval'd actual  ", evalActualOnce,
+              "\nright?",   evalExpectedOnce === evalActualOnce} ];
+      Print[ "" ]; (* newline *)
+      If[ evalExpectedOnce === evalActualOnce,
+          totalRight += 1,
+          totalWrong += 1 ];
+      {"total right", totalRight, "total wrong", totalWrong}
+      ];