Question: Are Edward Abbey and Harry Mathews both writers?

Context paragraphs:
Edward Abbey: Edward Paul Abbey (January 29, 1927 – March 14, 1989) was an American author and essayist noted for his advocacy of environmental issues, criticism of public land policies, and anarchist political views.  His best-known works include the novel "The Monkey Wrench Gang", which has been cited as an inspiration by environmental groups, and the non-fiction work "Desert Solitaire".

Harry Mathews: Harry Mathews (February 14, 1930 – January 25, 2017) was an American writer.  He is the author of various novels, volumes of poetry and short fiction, and essays.  Mathews was also a translator of French.

Desert Solitaire: Desert Solitaire: A Season in the Wilderness is an autobiographical work by American writer Edward Abbey, originally published in 1968.  His fourth book and his first book-length non-fiction work, it follows three fictional books: "Jonathan Troy" (1954), "The Brave Cowboy" (1956), and "Fire on the Mountain" (1962).  Although it initially garnered little attention, "Desert Solitaire" was eventually recognized as an iconic work of nature writing and a staple of early environmentalist writing, bringing Abbey critical acclaim and popularity as a writer of environmental, political, and philosophical issues.

Hayduke: Hayduke is a term and verb used among environmental activists and people who cite cult "revenge" books.  It is the name of George Washington Hayduke, a fictional character based on Edward Abbey's friend Doug Peacock in Abbey's cult classics "The Monkey Wrench Gang" and "Hayduke Lives! ".  The Hayduke character personified the "no compromise in defense of the Earth" approach to environmentalism, made real in early Earth First!  activism.

The Brave Cowboy: The Brave Cowboy (1956) was Edward Abbey's second published novel (as detailed in James M. Cahalan's biography of Abbey).

Trevor Winkfield: Trevor Winkfield (born 1944) is a British-born artist and writer.  Drawing upon his interest in both modernist literary movements and medieval architecture and pageantry, Winkfield has collaborated with many contemporary poets and writers, including John Ashbery, Harry Mathews, James Schuyler, and Ron Padgett.

Laura Duke Condominas: Laura Duke Condominas (also known as Laura Duke, born in Boston April 1951) is the daughter of French artist and film-maker Niki de Saint-Phalle and American novelist Harry Mathews.  As an actress she is most notable for her portrayal of Guinevere in Robert Bresson's film "Lancelot du lac" (1974).

Fire on the Mountain (Abbey novel): Fire on the Mountain is a 1962 novel by Edward Abbey.  It was Abbey's third published novel and followed "Jonathan Troy" and "The Brave Cowboy".

Jonathan Troy: Jonathan Troy (1954) was Edward Abbey's first published novel, as detailed in James M. Cahalan's biography of Abbey.  Only 5,000 copies were printed and almost immediately after it was released the author wanted to disown the work.  He asked that it never be published again, and it has not been, making it very rare and the only one of his eight novels that many Edward Abbey fans have not read.

Locus Solus (journal): Locus Solus was an American journal of experimental poetry and prose that published four issues in 1961 and 1962, one a double issue.  The magazine was edited by the poets John Ashbery, Kenneth Koch, and James Schuyler, all of whom contributed to its four issues.  The content was completely in English but the journal was published in France (in Lans-en-Vercors) by Harry Mathews.

Supporting paragraphs: Edward Abbey Harry Mathews
Answer: yes