gnu: Add texlive-tex.

* gnu/packages/tex.scm (texlive-tex): New variable.

gnu/packages/tex.scm

@@ -549,6 +549,43 @@ (define (substitute-commands scripts)
     (license (license:fsf-free "https://www.tug.org/texlive/copying.html"))
     (home-page "https://www.tug.org/texlive/")))
 
+(define-public texlive-tex
+  (package
+    (name "texlive-tex")
+    (version (number->string %texlive-revision))
+    (source (texlive-origin
+             name version
+             (list "doc/man/man1/initex.1"
+                   "doc/man/man1/initex.man1.pdf"
+                   "doc/man/man1/tex.1"
+                   "doc/man/man1/tex.man1.pdf")
+             (base32
+              "0njmxc6l84j44k48qh7d79n3qznzriz2pf8lkj09i7mkkj9fw9lf")))
+    (outputs '("out" "doc"))
+    (build-system texlive-build-system)
+    (arguments
+     (list #:texlive-latex-base #f
+           #:create-formats #~(list "tex")))
+    (propagated-inputs
+     (list texlive-cm
+           texlive-hyphen-base
+           texlive-knuth-lib
+           texlive-kpathsea
+           texlive-plain))
+    (home-page "https://ctan.org/pkg/tex")
+    (synopsis "Sophisticated typesetting engine")
+    (description
+     "TeX is a typesetting system that incorporates a macro processor.  A TeX
+source document specifies or incorporates a number of macro definitions that
+instruct the TeX engine how to typeset the document.  The TeX engine also uses
+font metrics generated by Metafont, or by any of several other mechanisms that
+incorporate fonts from other sources into an environment suitable for TeX.
+TeX has been, and continues, a basis and an inspiration for several other
+programs, including e-TeX and PDFTeX.  The distribution includes the source of
+Knuth's TeX book; this source is there to read, as an example of writing TeX ;
+it should not be processed without Knuth's direct permission.")
+    (license license:knuth)))
+
 (define-public texlive-bidi
   (package
     (name "texlive-bidi")