Celebratio Mathematica

D. John­son: Let­ter to J. Birman, un­dated. About sim­pli­fic­a­tions to proofs (based on phone call with Joan). misc

D. John­son: Let­ter to J. Birman, un­dated. About pa­per identi­fy­ing the ker­nel of one of “Joan’s” ho­mo­morph­isms. misc

D. John­son: Let­ter to J. Birman, un­dated. About pa­per enu­mer­at­ing ${\mathbb{Z}}_2$ maps, proof that all the 4-in­ter­sec­tion cases re­duce, and ma­ter­i­al on in­ter­sec­tion the­ory. misc

D. John­son: Let­ter to J. Birman, un­dated. About us­ing re­la­tions in $\mathcal{I}$ to get sym­met­ric ho­mo­logy spheres and new pa­per with de­scrip­tion of $\mathcal{I}/\mathcal{C}$. misc

D. John­son: Let­ter to J. Birman of 10 March 1977. Short de­scrip­tion of ma­chinery to be used in forth­com­ing pa­per. misc

D. John­son: Let­ter to J. Birman, un­dated. About pa­per on tor­sion of maps in $\mathcal{I}$. misc

D. John­son: Notes for J. Birman, un­dated. About the space of Cas­son ho­mo­morph­isms for a sur­face $K_{g,1}$. misc