feat:Surfaced &solve; preparation of &solve(expr, vars).

Author: antononcube

lib/CortexJS.rakumod

@@ -64,6 +64,22 @@ sub factor($expr) is export {
     return $ce.factor($expr);
 }
 
+proto sub solve($expr, |) is export {*}
+
+multi sub solve($expr, Str:D $var) {
+    return solve($expr, [$var,]);
+}
+
+multi sub solve($expr, @vars) {
+    start-ce() without $ce;
+    return $ce.solve($expr, @vars.join(', '));
+}
+
+multi sub solve($expr) {
+    start-ce() without $ce;
+    return $ce.solve($expr);
+}
+
 sub to-latex($expr) is export {
     start-ce() without $ce;
     return $ce.to-latex($expr);

lib/CortexJS/ComputeEngine.rakumod

@@ -82,10 +82,14 @@ method factor($expr) {
     $!backend.call('factor', :$expr);
 }
 
-method solve($expr) {
+multi method solve($expr) {
     $!backend.call('solve', :$expr);
 }
 
+multi method solve($expr, $vars) {
+    $!backend.call('solve', :$expr, :$vars);
+}
+
 method to-latex($expr) {
     $!backend.call('to_latex', :$expr);
 }