Podcast #128: We chat with Kent C Dodds about why he loves React and discuss what life was like in the dark days before Git. Listen now.

 4 Trakhtenbrot edited Oct 22 '16 at 11:58 Hendrik Jan 23k11 gold badge3030 silver badges7878 bronze badges Probably the notation originates from the "Finnish school". My copy of 'Formal Languages' by Arto Salomaa (Academic Press, ACM monograph series, 1973) uses $$\lambda$$ for the empty string. And so does his 1969 book 'Theory of Automata' (Pergamon Press). We move back. The classic 'Finite Automata and Their Decision Problems' by M.O. Rabin and D.Scott (April 1959) have the notation (capital) $$\Lambda$$ for "the empty tape with no symbols" (where a tape is a finite sequence of symbols). One of the early people to write on finite automata was Trakhtenbrot and he used a symbol much like $$\Lambda$$ but typeset as $$\land$$ (as in his book with Barzdin, 1970, my russian is lousy but I recognize $$\land p= p\land=p$$). Probably the notation originates from the "Finnish school". My copy of 'Formal Languages' by Arto Salomaa (Academic Press, ACM monograph series, 1973) uses $$\lambda$$ for the empty string. And so does his 1969 book 'Theory of Automata' (Pergamon Press). We move back. The classic 'Finite Automata and Their Decision Problems' by M.O. Rabin and D.Scott (April 1959) have the notation (capital) $$\Lambda$$ for "the empty tape with no symbols" (where a tape is a finite sequence of symbols). Probably the notation originates from the "Finnish school". My copy of 'Formal Languages' by Arto Salomaa (Academic Press, ACM monograph series, 1973) uses $$\lambda$$ for the empty string. And so does his 1969 book 'Theory of Automata' (Pergamon Press). We move back. The classic 'Finite Automata and Their Decision Problems' by M.O. Rabin and D.Scott (April 1959) have the notation (capital) $$\Lambda$$ for "the empty tape with no symbols" (where a tape is a finite sequence of symbols). One of the early people to write on finite automata was Trakhtenbrot and he used a symbol much like $$\Lambda$$ but typeset as $$\land$$ (as in his book with Barzdin, 1970, my russian is lousy but I recognize $$\land p= p\land=p$$). 3 added 302 characters in body edited Oct 19 '16 at 21:56 Hendrik Jan 23k11 gold badge3030 silver badges7878 bronze badges Probably the notation originates from the "Finnish school". My copy of 'Formal Languages' by Arto Salomaa (Academic Press, ACM monograph series, 1973) uses $$\lambda$$ for the empty string. And so does his 1969 book 'Theory of Automata' (Pergamon Press). We move back. The classic 'Finite Automata and Their Decision Problems' by M.O. Rabin and D.Scott (April 1959) have the notation (capital) $$\Lambda$$ for "the empty tape with no symbols" (where a tape is a finite sequence of symbols). Probably the notation originates from the "Finnish school". My copy of 'Formal Languages' by Arto Salomaa (Academic Press, ACM monograph series, 1973) uses $$\lambda$$ for the empty string. Probably the notation originates from the "Finnish school". My copy of 'Formal Languages' by Arto Salomaa (Academic Press, ACM monograph series, 1973) uses $$\lambda$$ for the empty string. And so does his 1969 book 'Theory of Automata' (Pergamon Press). We move back. The classic 'Finite Automata and Their Decision Problems' by M.O. Rabin and D.Scott (April 1959) have the notation (capital) $$\Lambda$$ for "the empty tape with no symbols" (where a tape is a finite sequence of symbols). 2 added link to Salomaa in wikipedia. edited Oct 19 '16 at 20:29 Hendrik Jan 23k11 gold badge3030 silver badges7878 bronze badges Probably the notation originates from the "Finnish school". My copy of Formal Languages'Formal Languages' by Arto SalomaaArto Salomaa (Academic Press, ACM monograph series, 1973) uses $$\lambda$$ for the empty string. Probably the notation originates from the "Finnish school". My copy of Formal Languages by Arto Salomaa (Academic Press, ACM monograph series, 1973) uses $$\lambda$$ for the empty string. Probably the notation originates from the "Finnish school". My copy of 'Formal Languages' by Arto Salomaa (Academic Press, ACM monograph series, 1973) uses $$\lambda$$ for the empty string. 1 answered Oct 19 '16 at 15:13 Hendrik Jan 23k11 gold badge3030 silver badges7878 bronze badges