--- /dev/null
+.\" This file is part of the Public Domain C Library (PDCLib).\r
+.\" Permission is granted to use, modify, and / or redistribute at will.\r
+.\"\r
+.Dd\r
+.Dt ASSERT.H 3\r
+.Os\r
+.\"\r
+.Sh NAME\r
+.Nm assert.h\r
+.Nd verify program assertion\r
+.\"\r
+.Sh SYNOPSIS\r
+.In assert.h\r
+.\"\r
+.Sh DESCRIPTION\r
+The header\r
+.In assert.h\r
+shall define one macro:\r
+.Dv assert(<scalar expression>) .\r
+.Pp\r
+If\r
+.Dv NDEBUG\r
+was undefined at the most recent inclusion of this header, then it shall be\r
+defined as a macro which will evaluate the scalar expression and, if it is\r
+false, abort the program with a descriptive error message as defined in\r
+.Xr assert 3 .\r
+.\"\r
+.Pp\r
+If\r
+.Dv NDEBUG\r
+was defined at the most recent inclusion of this header, then it shall be\r
+defined as a macro which evaluates as a void expression and\r
+.Sy does not\r
+evaluate its parameter.\r
+.\"\r
+.Sh STANDARDS\r
+Conforming to\r
+.St -isoC-90 ,\r
+.St -isoC-99 .
\ No newline at end of file