Wasn't MYCROFT an acronym for several words ?
NO !  The acronym was "Lunar infrastructure and machinery are largely 
managed and controlled by HOLMES IV ("High-Optional, Logical, 
Multi-Evaluating Supervisor, Mark IV"), the Lunar Authority's master 
computer, on the premise that having a single, large-capacity computer 
to run everything is cheaper (though not safer) than multiple 
independent systems.[5]"
    
https://en.wikipedia.org/wiki/The_Moon_Is_a_Harsh_Mistress
"The narrator is Manuel Garcia ("Mannie") O'Kelly-Davis, a computer 
technician who discovers that HOLMES IV has achieved self-awareness - 
and developed a sense of humor. Mannie names it "Mike" after Mycroft 
Holmes, brother of fictional Sherlock Holmes, and the two become 
friends.[6]"
I really need to read TMIAHM again, it is sitting in my SBR.  Along with 
the sequel, "The Rolling Stones", the final years of Hazel Stone.
Lynn