[R] R emulation of FindRoot in Mathematica

[Troels Ring]

Hi friends - I hope this is not a misplaced question. From the 
literature (Kushmerick AJP 1997;272:C1739-C1747) I have a series of 
Mathematica equations which are solved together to yield over different 
pH values the concentrations of metabolites in skeletal muscle using the 
Mathematica function FindRoot((E1,E2...),(V2,V2..)] where E is a list of 
equations and V list of variables.  Most of the equations are individual 
binding reactions of the form 10^6.494*atp*h == hatp and next 
10^9.944*hatp*h ==hhatp describing binding of singe protons or Mg or K 
to ATP or creatin for example, but we also have constraints giving total 
concentrations of say ATP i.e. ATP + ATPH, ATPH2..ATP.Mg

I have, without success, tried to find ways to do this in R - I have 36 
equations on 36 variables and 8 equations on total concentrations. As 
far as I can see from the definition of FindRoot in Wolfram, Newton 
search or secant search is employed.

I'm on Windows R 4.2.2

Best wishes
Troels Ring, MD
Aalborg, Denmark