[Diff since v4.2.0](JuliaSymbolics/Symbolics.jl@v4.2.0...v4.2.1)

**Closed issues:**
- can symbolic.jl solve a system of nonlinear equations？ (JuliaSymbolics#470)
- There will be a lot of warnings when using @register in 1.7  (JuliaSymbolics#478)
- `substitute` parsing error (JuliaSymbolics#480)

**Merged pull requests:**
- CompatHelper: bump compat for SymbolicUtils to 0.19, (keep existing compat) (JuliaSymbolics#475) (@github-actions[bot])
- Fix register fallback (JuliaSymbolics#488) (@shashi)
- Add states kwarg (JuliaSymbolics#489) (@YingboMa)

[Diff since v4.1.1](JuliaSymbolics/Symbolics.jl@v4.1.1...v4.2.0)

**Closed issues:**
- Evaluate NonlinearSystem at HomotopyContinuation variables/parameters (a problem with build_function/generate_function) (JuliaSymbolics#414)
- Auto-Parallel example fails on simplify(...) step (JuliaSymbolics#467)

**Merged pull requests:**
- CompatHelper: bump compat for SpecialFunctions to 2, (keep existing compat) (JuliaSymbolics#452) (@github-actions[bot])
- abstract type Operator (JuliaSymbolics#454) (@baggepinnen)
- CI to LTS (JuliaSymbolics#463) (@ChrisRackauckas)
- Corrected the output from f(u[1:4]) (JuliaSymbolics#466) (@NicholasWMRitchie)
- Fix auto-parallel tutorial (JuliaSymbolics#469) (@ChrisRackauckas)
- Remove destructive invalidation and fix compile times (JuliaSymbolics#471) (@ChrisRackauckas)

[Diff since v4.1.0](JuliaSymbolics/Symbolics.jl@v4.1.0...v4.1.1)

**Closed issues:**
- `scalarize` errors on vector inner products (JuliaSymbolics#417)
- Stackoverflow with array variable and registered function (JuliaSymbolics#436)
- `@register`ed functions with return type annotation doesn't produce requested return type (JuliaSymbolics#438)
- Adding two mat-vec-mul throws "key i not found" (JuliaSymbolics#448)

**Merged pull requests:**
- Don't recurs if we are done (JuliaSymbolics#433) (@YingboMa)
- Remove pirate `ndims` method (JuliaSymbolics#437) (@baggepinnen)
- more conscious sparse array handling in build_function (JuliaSymbolics#444) (@shashi)
- add jacobian method for Arr (JuliaSymbolics#445) (@baggepinnen)
- solve some bugs with get_variables on array variables (JuliaSymbolics#451) (@baggepinnen)
- WIP: @register changes (JuliaSymbolics#457) (@shashi)
- fix extruded dim in broadcast when all args have size 1 (JuliaSymbolics#458) (@shashi)

[Diff since v4.0.1](JuliaSymbolics/Symbolics.jl@v4.0.1...v4.1.0)

**Merged pull requests:**
- Semi-polynomial form (JuliaSymbolics#428) (@shashi)
- define `^` for difference (JuliaSymbolics#429) (@baggepinnen)
- Update `DiscreteUpdate` docstring (JuliaSymbolics#430) (@baggepinnen)

[Diff since v4.0.0](JuliaSymbolics/Symbolics.jl@v4.0.0...v4.0.1)

**Merged pull requests:**
- Add scalarize for equations (JuliaSymbolics#432) (@YingboMa)

[Diff since v3.5.1](JuliaSymbolics/Symbolics.jl@v3.5.1...v4.0.0)

**Merged pull requests:**
- Add Metatheory.jl and TermInterface.jl dependencies, update SymbolicUtils.jl (JuliaSymbolics#421) (@0x0f0f0f)
- fix substitute on array{num} (JuliaSymbolics#422) (@anandijain)

[Diff since v3.5.0](JuliaSymbolics/Symbolics.jl@v3.5.0...v3.5.1)

**Merged pull requests:**
- Fix issue JuliaSymbolics#389. (JuliaSymbolics#415) (@kllrak)
- Fix for mixed vector and scalar inputs for solve_for (JuliaSymbolics#419) (@owiecc)
- fix num/complex rule (JuliaSymbolics#420) (@hexaeder)

[Diff since v3.4.3](JuliaSymbolics/Symbolics.jl@v3.4.3...v3.5.0)

**Closed issues:**
- `substitute` on an `Add` errors when `dict::Dict{Num, Num}` but not `dict::Dict{Num, Real}` (JuliaSymbolics#392)
- Operation on symbolic Uniform scaling results in Matrix{Any} (JuliaSymbolics#406)

**Merged pull requests:**
- Some optimizations (JuliaSymbolics#410) (@YingboMa)

[Diff since v3.4.2](JuliaSymbolics/Symbolics.jl@v3.4.2...v3.4.3)

**Closed issues:**
- Proper `solve_for` for linear system of equations (JuliaSymbolics#222)

**Merged pull requests:**
- Minor optimization (JuliaSymbolics#405) (@YingboMa)
- Multivariate linear expansion and more robust solver for linear system of equations (JuliaSymbolics#407) (@YingboMa)

[Diff since v3.4.1](JuliaSymbolics/Symbolics.jl@v3.4.1...v3.4.2)

**Closed issues:**
- <ₑ(Symbolic, Num) is ambiguous (JuliaSymbolics#362)
- Calculus with Symbolic Arrays (JuliaSymbolics#387)
- Simplify does not fully simplifies (JuliaSymbolics#394)
- Checking equality of symbolic expressions  (JuliaSymbolics#401)

**Merged pull requests:**
- CompatHelper: bump compat for Setfield to 0.8, (keep existing compat) (JuliaSymbolics#377) (@github-actions[bot])
- fix substitute for Equation[] (JuliaSymbolics#393) (@anandijain)
- Fix typo from equations (JuliaSymbolics#399) (@Suavesito-Olimpiada)
- More robust scalar linear solve (JuliaSymbolics#403) (@YingboMa)